The General Permitted Development Order Part - 1 General Q & A DCP Section 4.34

This section deals with the interpretation of the principal provisions of the Statutory Instrument entitled Town and Country Planning (General Permitted Development) Order 1995 - as amended. It also covers the equivalent legislation in Scotland and Wales, both under review at the time of writing. However, information and commentary on the GPDO will concentrate on the English Order, to which radical and controversial changes to Part 1 were made in 2008.

Q & A Part 1 – General 4.34/101

If planning permission is given for a dwelling with a detached garage within 5 metres, should the volume of the garage be deducted from the permitted development allowance when considering any subsequent proposals for extensions? If this approach is taken it means in effect that any dwelling built with a double garage would have no subsequent permitted development rights for extensions.

Interpretation of the particular part of the General Permitted Development Order (GPDO) concerned with the five metre rule is a particular headache for practitioners as shown by the many appeal cases cited at (4.3446).  However, as one of the purposes of Part 1 of the GPDO is to place a ceiling on the amount of dwellinghouse extensions which may be built without planning permission, the inclusion of a garage built with planning permission can never have been intended.


I agree with your conclusion but that is not what the words in the General Permitted Development Order (GPDO) say. My authority continues to count garages built at the same time as the main part of the house under the same planning permission, and within 5 metres of the house, towards the cubic content figure.

A case reported in JPL in 1992 p.88 was clear that a detached garage within 5 metres of a dwelling must be taken into account when calculating the volume of the resulting building. This interpretation seems to follow the legislation but does defy logic. Are there any more recent cases which might clarify matters further?

A similar point has been made to my original reply emphasing the fact that if what the law states is clear and unambiguous then one should not try to interpret its intent.  It is ironic that a part of the GPDO that uncharacteristically seems to be regarded as clear and unambiguous should also be a completely irrational imposition. I shall be reviewing all the relevant cases in the next revision of Development Control Practice manual and any others that readers feel are relevant will be welcomed.

A local authority is insisting that there are no householder permitted development rights applicable to listed buildings but I see nothing in the Order to justify such a sweeping judgement. Who is right?

The Order states in relation to Part 1 Class A, which permits the enlargement, improvement or other alteration of a dwellinghouse, that the erection of any building within the curtilage of a listed building is not permitted. Therefore, on the face of these words, any extension to a dwellinghouse such as an additional room or garage would be a building for the purpose of this Part (but not works that constitute a mere alteration or improvement). However due to the fact that such a restriction within Class A is unnecessary as all works covered would be bound to require listed building consent anyway except freestanding structures within 5 metres of the dwelling, it may be reasonably concluded that the intention here was only to bring these latter developments at listed buildings within planning control. The remaining Classes in Part 1 do not have any restriction related to listed buildings save Class E which limits permitted development rights for garden structures within the curtilage of listed buildings to 10 cubic metres. The answer to your question is, therefore, that many householder permitted development rights do prevail at a listed dwellinghouse and the local authority are wrong to assert otherwise.

Are you aware of any definitions of what constitutes the curtilage of a dwelling?

Correct definition of the extent a residential curtilage is important due to the extensive permitted development rights for householders available therein. Consequently there has been extensive litigation on the subject.  There is no rule of thumb that may be applied as the courts regard each situation as one to be determined on its merits, but a fairly comprehensive summary of legal and appeal decisions is to be found in Development Control Practice. GH

If a detached property has a series of extensions equating to 70 cubic metres and one of these extensions is removed to facilitate a further extension, are permitted development rights reinstated for the cubic content of the demolished extension?

The volume of a permitted development extension and which was subsequently demolished is available to be set against further extensions. A 1999 appeal decision from Birmingham examined this proposition in the scenario where a new extension at a dwelling was being erected with the intention to demolish an existing extension on completion.  The inspector observed that at the point in time of the completion of the new extension there was a technical breach of planning control which was remedied on demolition of the older extension.

The GPDO does not allow a building or structure between a dwelling and the highway. But what is the position if there is already a detached garage or outbuilding within this area, or an attached outbuilding to the front of the house with access from the outside only?

The GPDO makes reference to the "original dwellinghouse" and therefore an assessment must be made in relation to the house as originally built or as existing in 1948. Thus if an attached outbuilding was contemporaneous with the house it would surely form the forward most part for the purpose of GPDO calculations regardless of whether there was internal access to the main house or not. As to a contemporary detached garage or outbuilding in the front garden it is unlikely that this would be considered to form part of the "original dwellinghouse". There are appeal examples which may be cited where it has been stated that this term does not refer to the generality of buildings on the land.

A detached farmhouse was partly demolished in the '70s leaving 75% of the original. This probably occurred for safety reasons. A two storey extension has now been commenced which is larger than the relevant PD tolerances. However with the new extension the total dwelling would be smaller than that of the "original" dwellinghouse as on 1/7/1948. Can you confirm that planning permission is required?

The GPDO allows the "original dwellinghouse" to be extended by 70 cubic metres or 15% whichever is the greater. As the base date in this case, as defined in the Order, is the appointed day one would have to look at the dwelling as it was then to make the necessary calculations. Even with a larger dwelling to play with than now exists, it seems unlikely this new extension would be less than 15%.


The 15% formula is to be applied to the resulting building which would be the farmhouse as now plus the proposed new extension. Comparing this resulting dwelling with the 1948 dwelling it would seem that the proposed extension would be permitted development.

What is the position regarding permitted development rights to the front of properties where the access road is in private ownership? This often occurs on newish developments where privately owned shared driveways serve 4 or 5 dwellings in a cul-de-sac. This would not seem to be the situation where the public have a right to pass and repass, as stated in a number of reported cases.

This question remains one to which there is no clear answer due to the lack of any definition in planning law as to what constitutes a "highway". As you say, various appeal decisions have seen inspectors fall back on common law usage. This has resulted in quite innocuous access ways, which have no other purpose but to provide secondary access to the rear of dwellings, being defined as highways. Using such restrictive interpretations there would seem to be little doubt that a shared cul-de-sac to the front of a few houses would also fall to be a "highway".

It seems to me that what the original draftsman of this requirement in the GPDO was fumbling for was a restriction on permitted development where this would impinge on a publicly visible space or domain framed by the frontages of dwellings. There would seem to be a clear public interest reason for such a control, which should apply to the situation you describe. However, a problem endemic to the GPDO is how to devise a legally watertight regulatory rulebook for concepts based on environmental perception. GH

I understand that for the purposes of the General Permitted Development Order 1995 (GPDO) "cubic content" is to be measured externally. If this is the case how should the creation of house basements be dealt with, as they do not have any external measurements?

The creation of basements is development as stated in the Town and Country Planning Act 1990 but the GPDO provides a cubic tolerance for the enlargement, improvement or other alteration to a dwellinghouse. However, the Order does not give any specific guidance as to how cubic content is to be measured other than, as you say, that it is to be calculated externally.  I do not have reference to a case where the permitted development status of residential basements has been directly argued. But in a recent appeal case from Tynedale, it was accepted by an inspector that only that part of a conservatory extension on sloping land that lay above ground should be cubed. Using this principle none of a basement totally below ground level would count against permitted development tolerances. Does any reader know of a ruling on this matter?


Section 55(2) of the Town and Country Planning Act 1990 states that works do not constitute development if they only affect the interior of a building or do not materially affect external appearance, but it is also stated that neither concession applies to additional space created underground. Therefore in a case where a basement has been constructed but some surrounding ground has been cut away to provide light and access, it is sensible to calculate by external measurement the volume thereby perceived as being above ground, anything else below ground level being discounted.

The question of the calculation of cubic content had considerable importance in determining the development charge levied under the 1947 Act, and detailed practice notes were issued by the Central Land Board. In the 1950s, in response to a question to my law lecturer at the UCL, the redoubtable J.J.Clarke confirmed that this basis still applied to other calculations under the Planning Acts. I do not have reference to the exact contents but they might provide the answer.

I have unearthed the document referred to, dated 1948, and here it clearly states that, for the purpose of cubing buildings, lateral measurements are to be taken from the external main wall faces at each floor level, whether above or below ground.

The definition of a classified road which is found in the Encyclopedia of Planning Law and Practice states that "for practical purposes the category includes all A and B roads which are not trunk roads."  However, the 1994 version of PPG13 avers in Annex B that a "classified road is defined in the General Permitted Development Order 1988 (GPDO); in practice it amounts to an A, B or C road which is not a trunk road." What is the correct interpretation for permitted development purposes?

The 1995 Order, as did its predecessor, states that the meaning of a classified road is to be derived from section 12(1) of the Highways Act 1980. This in turn derives a definition from a number of earlier enactments, including the Local Government Act 1967 which refers to the fact that roads may be classified I, II and III. Despite the Encyclopedia commentary, I think that the weight of evidence is that what are now A, B and C roads are "classified" for the purposes of the GPDO. However, an appeal case from Mid-Sussex last year showed that Highway Authorities may not always be able to produce evidence as to whether or not a minor road is classified as class C.

There is an irregular shaped piece of land at the end of my client's 15 metre long back garden, upon which is located an electricity sub-station. Located on the other side of this piece of land is an unadopted estate road, which at its nearest point to the garden boundary is over a metre. The planning authority contends that planning permission is required for a recently erected conservatory in the rear garden, on the basis that it within 20 metres of the highway. I maintain that there is a clearly defined break between the pavement of the estate road and the curtilage of my client's property. Please could you advise?

This conservatory would not be permitted development if the highway "bounds" the rear of your client's curtilage. I would have thought that if the land in question can reasonably be considered to be part of the verge of the highway, then the garden would bound that highway. This is the legal position in Scotland, but I do not have any case precedents to hand from other parts of the UK. Can any reader help?

My authority is considering taking enforcement action against the owners of a property where a single storey rear extension has been built which we believe to be in excess of the permitted development limit of 70 cubic metres. However, the ground around the extension has been built up by about half a metre above what we consider to be the original ground level.  Should we be taking the original or the new ground level when measuring the height element for the cubic content calculation required by the General Permitted Development Order 1995 (GPDO)?

Although article 1(3) of the GPDO states that height is to be measured by reference to "ground level", this is specific to references to "height" in the Order and is not relevant in this case.  The only guidance on the calculation of "cubic content" is at Article 1(2) where this term is stated to mean the cubic content of a structure of building as measured externally.  An appeal case from Tynedale determined last year was similar to the situation you describe and involved enforcement action taken against a conservatory where external ground levels had subsequently been altered. Here an inspector stated that "The council takes the cubic content to include all parts of the conservatory showing above ground level and, to take account of the continuous slope of the land, uses in the calculation an average of the heights above ground level at the rear and front of the conservatory respectively. I regard this as a reasonable and proper interpretation of the GPDO advice that cubic content is to be measured externally." The appellant's method of calculation using only the height above the highest part of the ground was rejected. While the written details relating to this written representations case do not make the precise physical situation entirely clear it would seem that this inspector was prepared to accept that those parts of the conservatory which were physically below ground level did not count toward cubic content.

I am looking to extend my house and have been told that I may not be able to as I will be building closer to a footpath at the side of the property which could be considered to be a highway. Is this correct?

The position is that extensions to dwellinghouses do not enjoy permitted development rights if located in the area between the house and "any highway that bounds the curtilage of the dwellinghouse", unless the "highway" is more than 20 m away from the house. There is no helpful definition in planning or highways law, but it is a conventional interpretation that a footpath, even if not a public footpath, may be a highway. Inspectors at appeal have on several occasions employed common law usage to assert that a highway is a way over which the public are entitled to pass and repass, including a footpath.

When dealing with an application for a roof extension where there is a detached garage or outbuilding within five metres of a dwellinghouse, is the volume of that building included when calculating the cubic content of the resulting building?

There is no doubt that the cubic tolerances available under part 1 of the General Permitted Development Order 1995 (GPDO) classes A1(a) and B1(d) are cumulative, but there has been contention as to whether a detached building within five metres should be included, as might be indicated by the provision at class A3(a)(ii). One view was contained in a 1996 lawful development certificate appeal decision from Barnet where a roof extension was argued to be permitted development. It was considered that the total resulting cubic content to be calculated included the appeal proposal, front and rear extensions, together with a detached garage within 5m of the dwellinghouse and that the totality of these volumes exceeded the 70 cu m tolerance available.

However, in a Reigate and Banstead case reported in Planning 22 February 2002 p.24  an inspector noted that A3 is stated in the GPDO to be applicable specifically "for the purposes of Class A". He reasoned that there was no justification for applying this provision to another class of permitted development. The logic of the inspector in the latter case was followed by a colleague in a further decision reported in Planning 21 June 2002 p17. Clearly these cases demonstrate two completely different interpretations of the provisions of the GPDO.  I can only ascribe the disparity to yet another failure by the authors of Schedule 2 to express themselves with clarity and precision.

I have a client who has remodelled a sloping rear garden on three levels. The top area by the house is a large level piece of ground which has been extended out 6m x 2m facilitated by the erection of large wooden retaining poles. The local authority is claiming that the importation of top soil constitutes an engineering operation. I consider that the works are permitted development or de minimis. Who is right?

It is a matter of fact and degree as to whether the deposit of the substantial amount of soil that must have been required for your client’s works is an engineering operation or not. Although you do not say exactly how many cubic metres of soil were needed, my opinion is that the sheer volume of material was probably such that operations were involved.

Part 1 classes E and F of the General Permitted Development Order 1995 do not permit engineering operations, only buildings, enclosures or hard surfaces, and part 2 class A does not allow a wall or fence that is not a means of enclosure. Therefore there are no permitted development rights that may be claimed.

If a building is converted to a single dwellinghouse and secures immunity from enforcement under the four year rule, does that immunity extend to the whole curtilage and bestow permitted development rights therein?

If a dwellinghouse has become lawful by the operation of the four year rule, it is reasonable that the curtilage associated with it during the requisite period also assumes the protection of the immunity given. Were this not so it would be open to a local authority to enforce within ten years against the domestic use of the land surrounding the residential building concerned, This would be a nonsense as it would act to deny a lawful use any access and amenity space.

The question of whether permitted development rights apply in this situation, has been the subject of departmental prevarication but it seems, from a reading between the lines of enforcement Circular 10/97 paragraph 2.81, that if a building is used as a single dwellinghouse and also looks like one to a reasonable person, then permitted development rights could apply. My own view is that if a building is a lawful dwellinghouse permitted development rights apply in all cases and it is not within the scope of ministerial power to deny such a right or attempt to make it conditional.

I have a query related to the interpretation of the term "highway" for the purposes of Parts 1 and 2 of the General Permitted Development Order 1995 (GPDO). Does a highway have to be used by vehicular traffic and is it relevant to consider whether the highway is public or private?

This is a frequent query sent in to Casebook Forum and follows from the complete lack of a definition in the current GPDO. At noted at (4.3442) common law usage is normally taken at appeal. This indicates that a highway is a way over which the public are entitled to pass and repass, including a footpath. As indicated by the appeal examples cited many "ways" which would not reasonably be considered a "highway" have been considered to be so. Clearly this is a matter which desperately needs clarification in the current review of the GPDO being undertaken by consultants.

Planning permission was granted for a small housing development and permitted development rights were not removed. Several of the units are occupied but in the case of one nearing completion the prospective purchasers have requested that a conservatory be erected at the rear. Such a conservatory would normally benefit from permitted development rights but the planning authority state that full permission is required. What is the correct position, given that the building is substantially complete and in my view constitutes a dwellinghouse?

I cannot identify a definitive ruling on the question of when dwellinghouse permitted development rights kick-in for new constructions, although it seems clear that the commencement of works has never been contemplated. There are at least three realistic possibilities a) when the dwelling is completed in terms of compliance with approved plans, b) when it is ready for occupation or, c) when it is occupied. Whatever threshold is taken, the length of time from the construction of the extension and the moment when it would otherwise qualify as permitted development, is never going to be long. This presents local authorities with a problem as to the reasonableness of any action to pursue an extension with a request for a planning application, as in your case, or with enforcement action. While it is clear that a local authority would be perfectly justified in law in seeking a planning application or indeed in taking enforcement action, there would seem to be little planning benefit in so doing, if a very similar extension may be erected with impunity after a few weeks.  For this reason I suspect that many local planning authorities tolerate house extensions erected before completion, and would be interested to hear if this is the case.

I would be interested in an opinion as to the extent of rights to extend, alter or improve barns once they have been approved for residential use. I believe it is common practice for LPAs to take away permitted development rights for under various classes within Part 1 of the GPDO. My specific query is with regard to restricting the later addition of windows.

There is no doubt that once a barn is lawfully occupied for residential purposes it becomes a "dwellinghouse" for the purposes of the GPDO and the various classes of permitted development which go with that status apply.  As development permitted contrary to normal rural restraint policies because it has been judged that the works involved would not be over harmful to the original character of a barn and its setting, it is almost universal practice for local authorities to conditionally remove any permitted development rights which could compromise this position. These normally extend to most of the rights contained in Part 1 and, if the circumstances justify it, may also embrace to the erection of fences as permitted by Part 2 . The insertion of additional openings in a barn conversion if one of the main problems that LPAs are wary of and the removal of Part 1 Classes A and B rights will secure that express permission is required for such works in the future.

My query relates to the demolished original element of a dwellinghouse in the context of permitted development rights for extensions to that property. The GPDO definition of original refers to a building existing in 1 July 1948 or as so built at a later date. It has been my understanding that if an original part of the dwellinghouse has been demolished, or would be demolished to facilitate a proposal, it is no longer appropriate to consider its volume in calculations of the "original dwelling".  However, another view has recently been put to me which is that in calculating the volume of extensions that may be taken as permitted development, account should be taken of the "lost" volume. I would appreciate any thoughts on the matter.

Those parts of the "original dwellinghouse" which have been demolished may be discounted for the purposes of calculating content. The Order makes it clear that for this exercise a comparison has to be made between the "original dwellinghouse" and the "resulting building " In the interpretation section of Part 1 it is stated that the "resulting building" means the building as to be enlarged "taking into account any enlargement, improvement or alteration to the original dwellinghouse". There seems little doubt that an "alteration" in these terms could be partial demolition and this has been accepted at appeal. Cases are described at (4.3446).

My authority has received an application for a domestic garage with a ridged roof 0.3m above the height at which it would be permitted development. It is felt that the building as a whole would be visually intrusive and harmful to the amenity of neighbouring residents. However, the applicant could with impunity build a slightly lower structure as permitted development. Is this a material consideration that the council should take into account?

This query exposes one of flaws of the current development control system which sets preconceived thresholds to determine what is permitted development and what is not. Inevitably it has been argued that these thresholds may be exceeded to some extent because the fallback allowed by the GPDO will produce a development with very similar characteristics and impact. The courts have held that such fallback may be a material consideration where there is a reasonable likelihood that if permission is refused, permitted development rights would be exercised. Particular reference should be made to the judgment in Burge v SOS & Chelmsford BC [1987]. In the case in point I advise that before it rejects the application your council should satisfy itself that the proposed garage would be significantly more harmful than the fallback position. It should also take into account the fact that a refusal, and the consequent erection of a permitted development garage, would mean the loss of the facility to impose conditions which could possibly mitigate the harmful impact you mention.

If I need to implement a use temporarily to gain rights to commence another without further planning permission, how long do I need to maintain it?

I imagine that this is a situation where there is some form of permission or permitted development right which is not actually desired, but if temporarily carried out will enable a lawful development which is required. A good example was demonstrated in a court case Kwik Save Discount Group v SOS & Oldham MDC 31/10/80 where a retailer acquired a building with permission for car sales and let it to a car concessionaire who occupied the building for just over one month. A supermarket use was then commenced and the LPA served an enforcement notice. It was argued that the permitted change of use from vehicles sales to retail use given by what is now Part 3 Class A of the GPDO, was applicable. An inspector held that the period of car sales use was de minimis and did not activate the retail right, and the court agreed.  Although this ruling establishes that 5-6 weeks is not long enough I do not know of any specific period of time that has been authoritatively held to be adequate for these purposes. This would normally be a matter to be determined according to the particular circumstances of the case, although I have heard of a rule of thumb period being cited in an LDC determination. This related to a structure within the curtilage of a dwellinghouse and the certificate stated it could be could be lawfully occupied as a residential annex "one year and a day" after its completion and used for non-primary accommodation purposes.

My client proposes to build an extension to the front of his property, which will be within permitted development rights provided that it is accepted that it is not within 20 metres of a highway. The drive serving the property is an unmade track serving half a dozen properties and comes to a dead end. Each property owns a proportion of the drive along their frontage and there would be no reason for the general public to walk or drive along the track other than to visit the properties. Would this track be defined as a highway for the purposes of the GPDO?

Definition of a highway for the purposes of the GPDO is a perennial difficulty, and has been raised several times before in Casebook Forum. Because of the lack of clear guidance in law the term has been subject to many different interpretations by decision makers. The interpretation that inspectors at appeal seem to favour at the moment is derived from common law usage. Which is that a highway is a way over which the public are entitled to pass and repass.  An appeal decision last year (Planning 28 June 2002 p22) may be helpful to your case as here an inspector added the criterion that a "highway" cannot include a private road, and went so far as to award costs against the local authority in question for failing to understand this. Here, the roadway in question served a small number of dwellings, and a notice was displayed that it was a private road and had not been adopted.

A company makes plastic one-piece canopies, which are bolted to the side wall of a house, to form a carport. There is no other means of support such as poles, brackets, or guy wires. I think that this is a built structure, and thus development, but does it have a volume? If so, this can easily be calculated, being the space underneath the surface of the canopy.

I agree that this form of canopy or awning could be considered a building operation and thus fall within the statutory definition of "development". However, I am not too sure that for permitted development purposes there is a volume to be measured as a cantilevered roof does not physically define any space, as would be the case if there were supporting legs. Does any reader know of this issue being explored?

A loft conversion of 50m2 is under construction at the moment. However there was an existing rear canopy which if added went over the permitted development limit of 70m3. I was informed by an enforcement officer that there was a breach of control and agree that this was correct.

The canopy should have been removed prior to construction and this has now been undertaken. To remedy the matter an LDC has been submitted to confirm that the dormer is lawful. Is this the correct format to use and will it be successful?

In the period during which the loft works were undertaken and the canopy still existed there was indeed a technical breach of planning control. This is assuming that the canopy did in fact have a volume that could be measured for the purposes of the GPDO. However, with the removal of the canopy the loft works would become permitted development, but in view of the council’s query it is entirely justifiable for you to ask for an LDC to safeguard your client's position should the property be sold.


I believe that the LDC application you propose should be refused unless it proposes the demolition of the dormer and the canopy extension, prior to the rebuilding of the dormer. This follows the reasoning of the judgment in Watts v Secretary of State for Transport, Local Government and the Regions [2002] (Planning 31 May 2002 p18).

A general exclusion from permitted development rights at Article 3(6) of the GPDO is development "that creates an obstruction to the view of persons using any highway used by vehicular traffic, so as to be likely to cause danger to such persons." Can the obstruction referred to be caused by physical works such as a building or enclosure, or does it relate to the obstruction created by vehicles using an access, such as on a blind corner?

This question was examined in an appeal decision from 1990 (DCS No. 547229) relating to an unauthorised access. Here an inspector felt that the meaning did not extend to the consequences of the development such as obstruction caused by vehicles emerging from the access, but was restricted to the direct effect of the physical act of development itself. It was reasoned that the wording of the Article made no reference to terms such as "results in" or "is likely to", it simply stated that permitted development rights were not available if the development "creates" an obstruction.

My client owns a detached house with a very large curtilage on the edge of a rural settlement. He has obtained planning permission to replace the existing house and erect another alongside within the curtilage. A condition withdraws permitted development rights for extensions and freestanding buildings. A number of the latter type of buildings and a swimming pool already exist on site away from the proposed two dwellings and the first part of my question is whether these structures can remain. If so can they be improved and altered at a later date without further permission. Finally I would like to know whether a freestanding building may be erected as permitted development prior to the implementation of the new development.

I assume that it is the intention to split the existing curtilage between the two new dwellings. There is no problem with regard to the retention of the existing outbuildings as presumably they will have been erected with the benefit of deemed permission and cannot be attacked no matter what the changed circumstances. However, when the closure of the existing house takes place it will cease to be a "dwellinghouse" and therefore no permitted development rights applicable to its curtilage will then be available. When the new houses are completed they would have brought about a return of normal householder permitted development rights for their respective curtilages, had not the condition you mention removed those rights. One course of action for your client is to carry out any works or alterations desired before the existing house ceases to be used as such. Another move could be to challenge the condition at appeal on the basis that it is not relevant to the development permitted, with reference to the cases described in Casebook (Planning 22 August p20 and 12 September p24).

We are dealing with a case where decking up to about 1.9m high has been erected across part of a very restricted domestic rear garden and this is causing problems for the neighbours.  As the decking is less than 2m high, is it permitted development or does it count as an extension to the dwellinghouse?

Similar questions have been raised before. In recent cases, Inspectors have considered that decking physically attached to and projecting from the rear wall of a dwelling and creating a measurable volume is a structure that may be considered to fall within Part 1, Class A, Schedule 2 of the GPDO 1995.  In other cases, decking may fall within Class E and is subject to the limitations set out thereunder.

My council is currently debating whether rear roof extensions that project out onto ‘back addition’ roofs fall within Class A or Class B of Part 1, Schedule 2 of the GPDO 1995. I think many councils treat most extensions that creep along the roof of the rear addition as roof extensions. Is this correct?

All extensions involving roof alterations fall within either Class B (roof enlargements) or Class C (other roof alterations), depending on whether there is a material alteration to the shape of the dwellinghouse.

Do railings above a rear extension of a dwellinghouse require planning permission? I believe that most authorities assess them against Class A of the GPDO. However, in cases where the property is not a dwellinghouse I think the approach is to argue that as railings would materially alter its appearance, they require permission, especially where intended to facilitate the use of a flat roof as a terrace. Is this correct?

Railings erected around flat roofs to form balconies or terraces are often considered to have a material effect on external appearance, although in many cases they will be permitted development by virtue of Classes B and C of Part 1, Schedule 2 of the GPDO. A roof terrace is not permitted by Class A as roof alterations are excluded, although it might be argued that the railings enclose a "volume" which should be counted against the available tolerance. However, in an appeal decided in 1987 it was held that balcony railings did not add any volume to a building while in another in 2000 it was found that the additional volume amounted only to the thickness of the railings themselves.

In Richmond-upon-Thames L.B. v SOS and J.Neale 1991 the High Court considered whether the erection of a parapet wall around the roof of a first floor extension to a suburban house in Surrey was permitted development. It was held that the wall fell to be considered against Class B of the GPDO and as the additional volume in the wall itself, which measured no more than 1 cu. m., did not exceed the relevant allowance, it did not require an express grant of planning permission. However, recommended changes to Part 1 of the GPDO in the recent review commissioned by the ODPM would specifically exclude roof terraces from the order.

It should be noted that in the case of R. (on the application of Cousins) v. London Borough of Camden 2002, the judge held that the erection of iron railings above a flat roof could not be regarded as an enlargement of a dwellinghouse consisting of an addition or alteration to its roof under Class B, Part 1, Schedule 2 of the GPDO 1995 but fell instead to be considered under Class C.


Further to previous views concerning the erection of railings to a balcony being permitted development under either Class B or C of Part 1, Schedule 2 of the GPDO could it not be argued that railings form a means of enclosure under Class A of Part 2 and are therefore subject to the 1m and 2m rule? If the railings were to a ground level patio, Part 2 would apply. Therefore if the patio is raised by virtue of being on top of an extension or other structure, would not measurements from the existing ground level indicate that any railing would require permission?

There is no precedent that supports this proposition. Rather than being considered under Class A of Part 2, as the top of a ground floor extension or structure will be its roof and the railings would result in its alteration, this type of development falls within its own Class, depending on whether there would be a material alteration to the shape of the dwellinghouse. My advice cites a recent court case where it was held that such railings should be assessed under Class C of Part 1.

An old un-extended house was converted to a residential home in 1978 and later extended in accordance with various permissions. In 1999 permission was granted for it to revert back to a dwellinghouse and the occupiers now want to build a small extension. Do they have any permitted development rights, or are these denied because the building has already been extended significantly when it was a residential home? Alternatively, if the house had been extended before 1978 using up permitted development tolerances, could the current occupants nevertheless claim 70 cubic metres of extension was permitted because the 1999 permission effectively created a new dwellinghouse?

Once the 1999 permission was implemented, there is no doubt in my mind that the new dwellinghouse acquired the usual permitted development rights, unless these had been withdrawn by condition. However, the development tolerances set out under Class A, Part 1, Schedule 2 of the GPDO 1995 are qualified by reference to the "original dwellinghouse", and in Article 1(2) "original" is defined as meaning "in relation to a building existing on 1st July 1948, as existing on that date and, in relation to a building built on or after 1st July 1948, as so built." Assuming that the house pre-dates 1948, in this case I think it could be argued that the extensions added during its time as a residential care home have used up the relevant permitted development allowances, and thus permission would be required for the new extension.

My client has been advised by a planning authority that her proposed loft conversion and dormer window require planning permission as "the part of the building to be enlarged would be within 2 metres of the boundary of the curtilage of the dwellinghouse and would exceed 4 metres in height (Schedule 2 Part 1 Class A (d) of the Town and Country (General Permitted Development) Order 1995". The authority also says that it only considers enlargement of dwellinghouses consisting of an addition or alteration to the roof under Class B if the dormer is set 1m in from the sides of the roof, 1m below the ridge and 1m from the eaves.  I cannot find any such interpretation of the Order in case law, so would appreciate your views on when is a roof extension a roof extension for purposes of Class B of the Order?

Loft conversions and dormer windows fall outside Class A and are assessed under Class B Part 1 Schedule 2 of the GPDO. Both case law and appeal decisions support this view, including one from 1996 where the Secretary of State ruled that proposed living rooms in the roofspace of a dwellinghouse, which included a significant change to the shape of the roof, fell to be considered under Class B. In a more recent case concerning a certificate of lawfulness, an inspector found that a loft conversion was permitted development under this class (Planning 9 January 2004, p20).

Although the GPDO has given rise to considerable difficulties of interpretation over the years, this cannot justify a planning authority imposing its own additional restrictions, such as those to which you refer. Moreover, provided your client’s proposal falls clearly within class B and meets the relevant tolerances, it is not affected by the fact that it offends a stipulation or exception in another, such as that set out at Class A (d).

We have recently obtained a lawful development certificate (LDC) for a dwellinghouse that was not built in accordance with the planning permission. Does this mean that the dwelling now has full permitted development rights? Development Control Practice says that the former DETR was apparently less inclined to the view that an LDC or immunity from enforcement confers any such rights, but there is no judicial authority for this. Has there been any more recent case law to update this view and does it apply equally to both certificates of lawful use and development?

The advice in the manual refers to Article 3 (5) of the GPDO 1995 which states that "the permission granted by Schedule 2 does not apply if a) in the case of permission granted in connection with an existing building, the building operations involved in the construction of that building are unlawful; b) in the case of permission granted in connection with an existing use." The wording was first introduced in a revision made to the 1988 GDO in 1992. Circular 17/92 stated that this change conferred any relevant permitted development rights to a use or operation the subject of an LDC. The same Circular confirmed that a development which was immune from enforcement was also lawful. It therefore seemed reasonable to deduce that permitted development rights apply to development that is lawful by reason of being in possession of an LDC or because of immunity from enforcement.

However, this advice in Circular 17/92 was not carried through into its successor Circular 10/97, and the resultant uncertainty continues to remain unresolved by case law. Nevertheless, it would appear that the editor of the Encyclopaedia of Planning is satisfied that once the restrictions imposed by Article 3 (5) are lifted with the passage of time, and the building operation or use becomes lawful under sec.191 of the 1990 Act for want of enforcement action, permitted development rights will become available.

My query relates to the definition of the "curtilage of a dwellinghouse" and whether detached parcels of land may be considered to fall within the main curtilage and therefore enjoy permitted development rights. For example, it is not unusual in country areas for cottages to have small parcels of garden on the other side of a front or rear access road.

Although close physical association is one of the usual tests for whether land falls within the curtilage of a dwellinghouse, cases tend to be interpreted on a matter of fact and degree basis. This has resulted in varied rulings, some of which are detailed in Development Control Practice at 4.3444.

We are trying to obtain a certificate of lawfulness for a builder who has built a roof extension on the rear slope of a dwelling. We contend that this is Permitted Development under Class B, Part 1, Schedule 2 of the GPDO 1995. However, the planning authority argues that, because the roof extension has been built off the main structure of the house, over its side and rear elevations and a side parapet wall, it should be classed as a "second storey extension" to the dwelling that falls to be considered under Class A, Part 1 of the Order. Who is right?

It is difficult to offer an opinion on this without an inspection of the site. However, all extensions involving roof alterations fall within Class B rather than Class A. In an appeal decision from 1995, the Secretary of State ruled that a roof alteration involving the removal of a flat roof from a rear extension, and its replacement by a pitched roof which then connected into the main roof, was permitted development within Class B. And in Hammersmith and Fulham LBC. v Secretary of State for the Environment [1993] the courts held that the term "height of the highest part of the existing roof" referred to the dwelling as a whole and not the particular part of the roof where works were to be carried out. In an LDC appeal case from Surrey in 2002 (DCS No. 31259684) an inspector cited Richmond LBC v SSE and Neale [1991] to support his conclusion that an existing enlargement of a dwellinghouse consisted of an addition or alteration to its roof and was thus permitted development under Class B. But where a dwellinghouse is otherwise enlarged, this will fall to be considered under Class A.

Over the years, my authority has granted several permissions for major residential developments that include conditions withdrawing permitted development rights for the enlargement, improvement or other alteration of the approved dwellinghouses. As a consequence, the authority now has a heavy workload of applications for minor extensions, all of which are non fee-earning and the vast majority are granted permission. Is there any mechanism by which the authority could revoke the relevant conditions, should it wish to do so, or must it live with the current situation in perpetuity?

I can see no obvious or easy solution. Provisions under sec 97 of the 1990 Act that enable a permission to be modified cannot be invoked as the development has been completed. In addition, powers under sec 73A to remove or vary the relevant condition can only be exercised on an application made to the authority. The only possible but probably extreme mechanism might be to serve a discontinuance order, which could include a new conditional permission under sec 102(2) of the Act. However, such orders are rare, are normally associated with enforcement action and require confirmation by the Secretary of State. I do not know if they have been used to achieve the objective you describe or whether this is a practicable proposition. Readers’ views are invited.


Regarding the query about an authority experiencing a heavy workload following the removal of permitted development rights on several housing estates, a solution would be for the Chief Planning Officer to apply to remove or vary the relevant conditions. That begs the question where the £110 application fee would come from. However, there appears to be nothing in planning law to prevent several estates being considered in one application, so only one fee would be payable. However, there would be an awful lot of notices to serve on landowners! Another more practical possibility might be the new power to make local development orders under the Planning and Compulsory Purchase Act 2004, although it remains to be seen how the relevant regulations are drafted and whether they would apply to this situation.

Several other readers have pointed out that the easiest way of dealing with this problem might be for the planning authority to apply to itself to remove or vary the relevant conditions. Where an application is in the public interest, it could be made by either a senior officer or the Chair of the Planning Committee. In addition, from my reading of section 40 of the new act, I agree that the use of local development orders appears worthy of serious consideration.

Further response

Regarding the query concerning heavy workloads following the removal of permitted development rights on several housing estates, the only solution my colleagues and I could think of was to get our Planning Committee to pass a resolution to say that it would not seek to enforce against x, y or z, subject to some safeguards on appearance, impact and so forth. This worked well enough originally, but with the increase in local politics and neighbour participation, it may now be difficult to persuade councillors that reducing the caseload like this is a good idea. It has to be remembered that while the public may have an opinion about big applications in their area, for most it is their neighbour's extension that is their sole contact with the planning system and possibly one of the biggest events of their occupancy. There may also be legal considerations.

A pair of adjoining cottages, one of which had been extended in accordance with a planning permission, was converted recently into a single dwelling. A large shed has been erected within 5m of the un-extended cottage. Bearing in mind its history, what permitted development rights does the property now enjoy?

I am not aware of any precedent that would shed any light on this. One possibility is that a new planning unit has been created, opening a new chapter in the history of the property. Thus for the purposes of the GPDO, the conjoined dwelling becomes the ‘original’ dwellinghouse with a fresh set of rights. Another is that it carries forward the rights already used-up by the previously separate dwellings, based on the notion that they still exist as such. However, that then raises the complicated issue of how the relevant tolerances should be calculated. Should they be assessed individually, or amalgamated with all the extensions carried out to both since 1948 deducted to leave a residual allowance, or should the extensions count against only one set of tolerances as the new property is now a single dwelling? The correct approach is unclear. Readers’ views are therefore invited.


I do not think this results in a 'fresh set' of rights. The allowance ought to be 70 cubic metres minus any existing extensions since 1948 and curtilage buildings within 5m. As the conversion did not need permission, the authority had no opportunity to withdraw such rights by condition, if necessary, to prevent harmful extensions. If the building is given a fresh set of rights then its occupiers could erect harmful extensions without permission and there would be no control over these. In this case, one of the cottages had been extended and there was a shed within 5m, so it is likely that most if not all of the permitted development tolerances have been used up.

I read the recent report on the ODPM statement relating to its proposed "Householder Development Consents Review". However, the announcement does not refer to the massive Lichfield research report on Permitted Development Rights carried out for the Government in September 2003. Are we to assume that this study, which devoted much of its efforts to the continuing problems created by the householder class, has been subsumed into this new review and as a result we will all have to wait a further indefinite period for these desperately needed reforms?

Since the consultants delivered their comprehensive report detailing various findings and recommendations, there has apparently been little progress on this matter and no consultation paper has emerged from the ODPM. Instead, there is to be another review guided by a working party whose membership is currently incomplete. As you say, there is no mention of the research report in the documents published alongside the planning minister’s recent statement and its status remains unclear. However, it is evident from the queries raised by readers in recent years that there is an urgent need to reform the current system of permitted development rights as this gives rise to many time-consuming disputes. Perhaps a reader from the ODPM will clarify the situation?

My authority has had several questions recently on what is a highway, in connection with dormer windows and whether the roof slope fronts a highway. Is there a common definition of what is a 'highway'?

The term is not defined in the General Permitted Development Order or elsewhere in planning legislation. While decision-makers often rely on the definition derived from common law usage, a footnote to paragraph 24 of Circular 9/95, which accompanied the Order, explains that a highway includes "all public roads, footpaths, bridleways and byways over which the public have a right to pass". The "Review of Permitted Development Rights" carried out by consultants on behalf of the government in 2003 recommends a new definition but no further action has apparently been taken on the report’s findings.

The owner of a house that has been converted into flats wishes to demolish the original front boundary wall and rebuild it to the same height but in different materials. Presumably this is permitted development, but could can an Article 4 direction be served on a building containing flats to restrict any such alterations?

Class A, Part 2, Schedule 2 of the General Permitted Development Order 1995 only grants permission for a replacement wall of no more than one metre in height above ground level where it does not enclose a listed building and is adjacent to a highway. Article 4(1) provides that a direction may be made to withdraw any permission granted by the Order with the exception of those available under Class B of Part 22 and Class B of Part 23. Appendix D to Circular 9/95 explains that Article 4 directions should be made only in exceptional circumstances and will rarely be justified unless there is a real and specific threat. Such directions are usually made in conservation areas and I have never come across one that relates to an individual building. Paragraph 9 of Appendix D suggests that this might be possible in the case of Part 1 rights for houses, but only where the house is of a particularly high quality. I think it doubtful that a direction withdrawing rights under Part 2 for minor operations to an individual building would be justified.

An inspector held that it was necessary for two opposite slopes to meet at the top of a roof to create a ridge (DCS No 100039198). I concur with the appellant's view that a mono-pitched roof has a ridge. Manufacturers’ literature includes references to mono-ridge and mono-pitched ridge tiles. The dictionary defines "ridge" as the junction of two sloping sides. The fact that one of the sides is at a slope of 90 degrees does not invalidate this definition. As an architect with more than 30 years’ experience of identifying the top of a mono-pitched roof as a ridge, is there any other evidence to suggest otherwise?

While I am not aware that this issue has come before the courts, the inspector’s approach was consistent with that taken in previous appeal decisions.

My previous authorities always took the view that if a proposal encroaches onto land outside the applicant’s ownership it would require planning permission, even where this is granted under the General Permitted Development Order (GPDO) 1995. Examples of such incursions include footings, guttering and the tying-in of an extension. However, some officers at my current authority dispute this approach. Who is right?

The general rule is that matters of ownership are immaterial to the consideration of whether a development requires permission. There is nothing in Article 3 of the GPDO that stipulates that permitted development rights do not apply where a proposal encroaches onto land in a different ownership. While it may be argued that a development that strays beyond a residential curtilage no longer enjoys the protection of Part 1 of the Order, which includes rights to erect certain extensions and outbuildings within the curtilage of a dwellinghouse, in my view the examples you give are minor transgressions and are therefore de minimis. In a decision from London in 1986, an inspector held that foundations that spread into another curtilage enjoy the permitted development rights accorded to the adjoining dwelling. This approach was endorsed in a case from 2001 (DCS No: 55430938) where a party wall on which a loft extension relied was held to fall within the curtilage of the house concerned for the purposes of the Order, even though that might not be so in conveyancing terms. So I agree with your present colleagues.


I disagree. I accept that there is nothing on the matter in Article 3 of the General Permitted Development Order 1995, but it is necessary to look at the heading of Part 1, Schedule 2. This refers to "development within the curtilage of a dwellinghouse". The fact that "dwellinghouse" is in the singular is critical to its interpretation. Class A permits the enlargement, improvement or other alteration of a dwellinghouse, again singular. If part of an extension encroaches on another residential curtilage the development does not relate to a dwellinghouse but to dwellinghouses. I therefore consider that permission is required because the development is not within the curtilage of a dwellinghouse. This is reinforced by the wording in the interpretation of Class A at paragraph A.3(b), which refers to other buildings in the same curtilage, again singular. When the Order is reviewed, the legislators have an opportunity to include clear guidance and, by using appropriate wording, to ensure consistent interpretation.

Although my advice was based on previous appeal decisions, as acknowledged in my reply, the matter is clearly arguable.

Is a river a "highway" for the purposes of planning control? My authority has a large navigable river running through its area and someone wishes to extend their dwelling towards it and within 20m. Would this require express permission?

The term "highway" is not defined in the General Permitted Development Order 1995 and is the subject of a recommendation in the ODPM review published in 2003. However, a footnote to paragraph 24 of Circular 9/95, which explains the Order, advises that it includes "all public roads, footpaths, bridleways and byways over which the public have a right to pass". Sec. 336 of the Town and Country Planning Act 1990 states that the term has the same meaning as in the Highways Act 1980. This makes it clear that "highway" means the whole or part of a highway other than a ferry or waterway. So the proximity of any house extension to the river in your area will have no bearing on the permission granted under Class A, Part 1, Schedule 2 of the Order.

There is disagreement in my office over whether the volume of an existing extension, such as a non-original garage within 5m of a house, set for demolition can be offset against the allowances under Classes A and B, Part 1, Schedule 2 of the General Permitted Development Order 1995. A colleague recalls an unidentified case from 1957 which stated that permitted development is for "once and for all" and that express permission is required for any subsequent extensions, even if previous extensions have been demolished. However, the advice in 4.3446 contradicts this. Can you shed any further light?

I cannot find a case that fits the description given by your colleague. Although the courts have held that the rebuilding of a house in stages falls outside the scope of the Order, they do not appear to have addressed specifically whether the demolition of any part of it can be offset against the allowances under Classes A and B. These take the "original dwelling" as the starting point, with "original" defined in Article 1 of the Order as meaning "in relation to a building existing on 1 July 1948, as existing on that date and, in relation to a building built on or after 1 July 1948, as so built". In my view, provided any enlargement of the original house is within the relevant limitations, the volume of extensions previously present at a house but later demolished should be subtracted from the permitted development allowances. This approach was taken in a decision from Oxfordshire in 2001. The inspector held that a proposed extension was permitted development, even though it exceeded the relevant allowance, as it would be offset by the demolition of a garage forming part of the original dwelling. An appeal decision from London in 2003 also supports this view (DCS No: 30842374).

My authority is receiving an increasing number of enquiries on domestic wind turbines. Whereas the need for express permission for turbines attached to a dwelling can be related to Classes A, B and C of Part 1, Schedule 2 of the General Permitted Development Order 1995, do free-standing turbines in residential curtilages fall to be assessed against Class E? If so, is the relevant height limit 3m or 4m? Are you aware of any relevant material considerations or case law?

I can find no case where the need for permission for such proposals has been considered. As you say, any turbine fixed to the roof or side of a dwelling falls to be assessed against the provisions of Classes A to C because these deal with enlargements and alterations to dwellinghouses. Among other things, Class E permits the provision in the curtilage of a dwellinghouse of any "building". Article 1 of the Order explains that a building includes "any structure or erection" but not "plant or machinery". The courts have held that a "chattel", such as plant and machinery, may be distinguished from a building operation by reference to three key factors - size, permanence and physical attachment to the ground. Given this test and the requirement for free-standing domestic wind turbines to be mounted on a tall tower or pole, they will constitute development in almost every case. The permitted height limit under Class E is 3m because the higher limit refers to buildings with a ridged roof. Permanent free-standing domestic turbines higher than 3m will require express permission. The possible effects of a proposed turbine will have no bearing on the need for permission. Technical Annex 8 to the companion guide to PPS22 includes useful guidance on the relevant planning issues.

A local authority has advised my clients that roof alterations to form rear and side dormer windows are permitted development. They also have permission for a single-storey rear extension and a front dormer window. What are the implications of constructing both sets of works concurrently?

A similar scenario was considered in R ex parte Watts v SOS [2002]. Mr Watts had permission for an extension but also wanted to build a roof extension at the same time under permitted development rights. The planning authority maintained that although the roof extension was in itself permitted development, when taken with the authorised extension it exceeded the tolerances under the General Permitted Development Order (GPDO) 1995 and thus required express permission. In reviewing an inspector's decision to uphold an enforcement notice, the courts held that the timing of such building works is important. Where development is carried out in accordance with the Order, its support is required until the works are substantially complete. If, before that happens, the dwelling is otherwise enlarged, improved or altered so that the total volume of all the works exceeds the relevant allowance, the potentially permitted development would no longer be protected. So your clients’ dormers would be permitted development if built before the extension, but not if they are constructed afterwards.

My client recently applied for a lawful development certificate to confirm that the construction of a porch for a rear door of a house and the insertion of a window in its front roof slope is allowed under Classes D and C, Part 1, Schedule 2 of the General Permitted Development Order 1995. It was refused on the grounds that the porch comprised an extension and when added to an existing enlargement exceeded the allowances under Class A. The authority refused the rooflight under the same class. What is your advice?

Class D grants permission for the construction of a porch "outside any external door" to a dwellinghouse subject to certain limits on its height, ground area and distance from a highway, including a footpath. Unlike Class A, the right is not restricted by reference to the structure's volume. This means that the porch may be built as permitted development after the allowances for house enlargements under Classes A and B have been used up, provided the relevant criteria are met. However, by virtue of paragraph I to Part 1, if the porch you mention was built before the extension, the volume that it encloses must be included in that of the "resulting building", and thus be deducted from the relevant allowances under Classes A and B when deciding whether an enlargement is permitted development. So while in either case a porch meeting the limitations of Class D would be lawful, depending on the timing of its construction, the existing extension may not. Assuming that the rooflight already exists, if it projects significantly above the roof slope this might have taken it out of Class C so that it would need to be assessed as an enlargement under Class B and not Class A. It may not therefore be lawful. The planning authority's approach to determining the application seems confused.

Express permission to retain a house extension was sought after it was noticed that the volume of a garage within 5m had not been taken into account when considering whether it was permitted development. The application was refused for design, character and amenity reasons. However, enforcement action is not being pursued as the garage has now been demolished. Can permitted development rights be obtained retrospectively and what is the status of the extension now that it is being allowed to remain?

As noted in my reply to a previous query, the courts do not appear to have specifically addressed whether the demolition of any part of a dwellinghouse can be offset against allowances under Classes A and B, Part 1, Schedule 2 of the General Permitted Development Order 1995. Inspectors generally adopt a pragmatic approach. If the enlarged building does not exceed the volumetric allowance compared to the "original dwellinghouse", it is difficult to argue that there has been a breach of control and that permitted development rights do not apply. There may be some situations, such as this one, where the planning system is made to look foolish. In my view, however, the extension is lawful and the authority is right not to pursue enforcement action.

Can a transparent canopy with two open sides that is attached to the rear of a house and covers a patio be defined as a building containing a volume?

I assume that the canopy takes the form of an awning that, while fixed to the wall, is otherwise unsupported. If the canopy has a material effect on the house - and this may be debatable if it is transparent - it will constitute development. In that event, for the purposes of determining whether the canopy should count against the volumetric allowances set out in Class A, Part 1, Schedule 2 of the General Permitted Development Order 1995, it must enclose some space. While the extent of such enclosure is debatable, an open-sided structure is unlikely to be considered to physically or visually enclose any space. Bearing in mind the judgment in London Borough of Richmond-upon-Thames v Secretary of State for the Environment [1991], it is possible that the canopy itself would count against relevant allowances, depending on the nature of its construction. However, this would be limited to the volume of the structure.

If the installation of a satellite dish on a house is development, albeit allowed under the General Permitted Development Order (GPDO) 1995, would a wind turbine not exceeding one metre in diameter on the gable wall of a house also be development? Also, am I correct in thinking that express permission would not be required for a turbine fixed to a house roof provided the installation does not project above the main ridge?

I can find no case that has considered whether a small domestic wind turbine constitutes development or requires permission. However, a turbine fixed to the dwelling will involve a building operation. Whether this is development for the purposes of planning control turns on whether it would materially affect the external appearance of the building, in accordance with Sec. 55(2) of the Town and Country Planning Act 1990. Applying the test established in Burroughs Day v Bristol City Council [1996], there may be circumstances where it would be considered not to have a material effect. Where that is the case, an installation on the wall of a house should be assessed against the provisions of Class A, Part 1, Schedule 2 of the GPDO. Provided it meets the conditions under that class, express permission would not be required. Where the installation is fixed to the roof it should be judged against the limitations of Class B. Express permission would not be required if the turbine does not project above the highest part of the roof and satisfies the remaining conditions in that class. The Government recently announced (Planning, 30 June, p2) that it is to relax development restrictions on domestic wind turbines.

My authority is getting an increasing number of enquiries on the need for permission for domestic wind turbines. A leaflet from a leading DIY retailer that now sells such installations states that unless the householder lives in a conservation area or listed building, it is unlikely that permission would be required. It adds that turbines have been incorporated into the General Permitted Development Order (GPDO) 1995 and are classed similar to a satellite dish. What is your view on this?

I have seen this leaflet and the advice it contains is incorrect. Where a small turbine is fixed to a house and would materially affect its external appearance, it will constitute development. If installed on a wall, the turbine should be assessed against Class A, Part 1, Schedule 2 of the Order. Provided it meets the conditions under that class, permission would not be required. Where it is fixed to the roof, a turbine should be judged against the limitations of Class B. Permission would not be required if the turbine does not project above the highest Part of the roof and satisfies the remaining conditions in that class. A free-standing turbine that comprises development should be assessed under Class E. So if it exceeds 3m in height, permission would be required. Although the Government announced this summer [2006] that it will relax development restrictions on domestic wind turbines, no changes have yet been made to the GPDO. Instead, it has been suggested that local development orders might be used to extend permitted development rights for small-scale renewable energy schemes.

Class E, Part 1, Schedule 2 of the General Permitted Development Order (GPDO) 1995 gives permitted development rights for "any building or enclosure, swimming or other pool" subject to certain conditions. The definition of a building for the purposes of the Order does not include any plant or machinery. My authority's view is that a turbine would be plant or machinery. So it would not be permitted development, although the associated pole could be, subject to relevant conditions. What are your thoughts on this interpretation?

You suggest that a garden turbine more than 3m high would need permission as a curtilage building. However, the limit may be 4m if an inspector rules that a turbine does not have a flat roof, which they generally do not have, so it can somehow be deemed to have a "ridged roof" for the purposes of permitted development. Should the Government not resolve this before it leads to problems?

What is the position on the installation of domestic turbines on curtilage buildings?

As has been pointed out Class E does not grant permission for "plant and machinery". The definition of a "building" for the purposes of the GPDO differs from that given at Sec. 336(1) of the Town and Country Planning Act 1990. The latter states that a building does not include plant or machinery "comprised in a building". The distinction is unclear. Neither do the Order's definitions of "plant and machinery" shed any light on the meaning of those words. However, the general approach is that plant and machinery are chattels that may be distinguished from operational development by reference to their size, permanence and physical attachment to the ground. In my view, a residential free-standing turbine considered plant or machinery would not need permission because it would involve a use that is incidental to the dwellinghouse in accordance with section 55(2)(d) of the 1990 Act. Where operational development is involved, the turbine should be judged against Class E. Although it is debatable whether the height limit should be 3m or 4m, most turbines are likely to be higher. One attached to a curtilage building should first be assessed to see whether it has any material effect on its external appearance. Where that is the case, the installation should be considered as an alteration to the building and considered under Class E.

Permission was granted in 1973 for a house followed closely by permission for a single-storey rear extension. The house and extension were constructed together in a single building operation, as evidenced by their continuous foundations and uninterrupted external brickwork. Do you agree that the original dwellinghouse in this case includes the extension?

Article 1(2) of the General Permitted Development Order (GPDO) 1995 defines "original" as meaning a building as existing on 1 July 1948 and, in relation to a building built on or after that date, "as so built". The latter words clearly cover the type of circumstances you describe. Therefore the extension forms part of the original dwellinghouse.


While I agree with your advice, if the foundations and walls are continuous they must have been built at the same time. Therefore, although they are now immune from action, both the dwelling and the extension must be unauthorised. Permission cannot be granted for an extension to a building that does not exist. If the house were built at the same time as the extension, the resulting building is not the house that had been permitted. The obvious solution would have been to have applied to build a different house type - the one with the extension. The applicants could then choose which house they built. This would also be the cheaper option because no fee is payable for the resubmission. I often encourage major house builders to apply for an estate of houses with conservatories, which are then optional extras, depending on customer demand. While this makes no difference to the query, it does raise an issue that many practising in development control must come across. Your views would be helpful.

I agree that planning permission should not be granted to extend a dwelling that has not yet been built. However, where separate permissions have been granted for a new house and for its extension before it is completed, it seems perverse and of little relevance to regard the built structure as being unauthorised.

A householder built a single-storey rear extension in 2000 as permitted development. He has recently completed a dormer loft conversion that would be permitted development were it not for the ground floor extension and which he accepts is unlawful. However, would this become lawful if the householder were to remove the rear extension? Or is the lawfulness of a development determined at the time of its completion, once the four-year immunity period has passed or when permission is granted? I can find no authority that governs such a situation and have heard differing opinions. IT.

For the reasons given in my advice to AS (Planning, 24 August, p25), if the ground floor extension is removed in my view this would make the loft conversion lawful. Paragraph 8.3 to Circular 10/97 explains that by virtue of Section 191(2) of the Town and Country Planning Act 1990 uses and operations are "lawful" if no enforcement action may be taken against them and they are not in contravention of any enforcement notice which is in force. This would apply once the time-limit for taking enforcement action has passed or the development is authorised by a permission, including that granted by a development order. PM.  


In Watts v Secretary of State for Transport, Local Government and the Regions 19/4/02, the court held that inherent in the GPDO was a degree of artificiality in that its availability depended on which works were done first. So if between the start of works and their conclusion the building was otherwise enlarged, improved or altered so that the cubic content of the resulting building together with the GPDO works would be more than relevant allowance, the GPDO works would cease to be protected. The court went on to find that prospective cubic content, however imminent, was to be ignored because once prospective cubic content became relevant one would be driven to accept as relevant that which might never exist as cubic content. It follows that prospective demolition must be ignored for the same reasons. The GPDO grants permission for development in the making not for the retention of that which has already been done. A number of inspectors have taken the same view. NW.

Further Response

In his reasoning PM relies on a different case (Planning, 24 August, p25). The two are distinguishable. In IT’s case the rear extension was not demolished before the dormer was constructed. The Article 3(1) permission enables development to commence and, provided it remains within the terms of that permission from the outset and during construction, the development benefits from the permission upon substantial completion. If it exceeds the permitted development limits it cannot benefit from the GPDO permission, is unlawful and can be enforced against. Albeit in different circumstances that is to be found in R (oao Watts) v Secretary of State for Transport, Local Government and the Regions [2002]. So the issue is whether an Article 3 permission can be gained retrospectively. I find nothing in the 1990 Act or the GPDO to suggest that it can and it is now too late to rely on the order’s protection through demolition. Of course a permission under s73A may be sought, but the dormer would stand to be considered on its merits with or without the rear extension. AK.

An intrusive 2m high and 150m long fence has been erected in a conservation area near the curtilage of a significant listed building. I consider that the local authority should have served an Article 4 Direction removing permitted development rights to put up fencing in the conservation area. It was first notified of the fence when only a few posts were in the ground. In defence of its decision not to serve a   direction the authority argues that ‘once work on the fence had commenced, the issuing of an Article 4 Direction would not have prevented further work on the fencing in question or any further works relating to this fencing’. On what basis can the authority’s interpretation be correct? MS.

The local authority’s position is right. Once a deemed permission granted by the General Permitted Development Order has been implemented by the commencement of work, it is regarded in the same way as any  conventional express approval for development. It may be lawfully completed, assuming the whole process is seen to be part of a continuing operation. Therefore, service of an Article 4 Direction has no inhibiting effect on permitted development operations already underway at the time. I am in no doubt that even the setting of just a few posts would be regarded as commencement of the fence you describe. GH.

My local authority has recently granted permission for a substantial replacement dwelling with permitted development rights removed for extensions and outbuildings. However, before commencing any work the developer has constructed a detached garage adjoining the existing dwelling, and also a large outbuilding in the rear garden. It is accepted that both would be permitted development in relation to the existing house. The new garage is sited and designed so that it could become attached to the new house when built. The developer has declined to stop work and enforcement is being considered. Is there any legal scope to stop this blatant attempt to subvert planning control and to achieve, by the back door, a larger development than the council is prepared to accept? DG.

In this case the important point to establish is whether, at the time of the construction of the new buildings, the original house remained a lawful ‘dwellinghouse’ to which permitted development rights would still apply. Definitions in planning law do not provide an answer, but the court led tests for abandonment of use may be applicable. If the original residential use remains capable of resumption, and no works have been commenced  to demolish the house and implement the planning permission for a replacement dwelling, my feeling is that the building is still lawfully a ‘dwellinghouse’. I agree that what has taken place seems to be a cynical manipulation of the planning system. Forum will be very interested to hear of any reader’s experience with this issue.GH.

The Mendip AONB Service is concerned about the increasing impact of horse related activities on landscape character and has encountered different interpretations of planning law by planning authorities in relation to certain activities. These centre on a) whether the use of a field for the grazing and exercising of horses requires planning permission, b) whether a ‘manege’ is development, and c) when does a field shelter become mobile enough to escape the need for permission? JR.

There can be few areas of planning control which raise so many legal difficulties in establishing whether permission is required. Your first query is the most contentious, as the outcome of court cases, particularly Sykes v Secretary of State for the Environment [1981], has placed planning control into the invidious, some have said ludicrous, position of having to distinguish between horses that are grazing land, and horses that are kept on land. The former is not a material change from agricultural land, while the latter is. The matter is fully debated in Development Control Practice at (4.3441) and (23.2111). The remaining two parts of your query relate to whether or not works are substantial enough amount to operational development requiring planning permission by reason of size, degree of permanence and physical attachment to land. This can be very much a matter of judgement depending on the facts of each case, and thus inconsistency is bound to occur between one authority and another. However, in the case of maneges there is less room for interpretation difficulties as such developments normally involve roof structures, lighting columns and fences as well as substantial engineering works to create a flat area with suitable drainage and surfacing. I would hazard that only a very rudimentary manege, involving only the spreading of a surface such as bark chippings, would be likely to escape planning control. With regard to field shelters appeal cases have shown very varied approaches, as demonstrated in Development Control Practice at (23.213). GH.


In his response to a query as to whether so called mobile horse shelters require planning permission (Planning 1749 14 December 2007) GH correctly stated that many of these may not be development. We at the South Downs Joint Committee believe that the government should recognize the visual impact of such structures and include them in the definition of development. There is also uncertainty as to whether permanent structures for grazing horses benefit from Part 6 permitted development rights if they are located on an agricultural holding. In such cases where they fall within the Class limitations would they not be deemed reasonably necessary for the purposes of agriculture notwithstanding the section 336 definition of agriculture in the Town and Country Planning Act 1990? MS.

Further Response

I wholeheartedly agree that planning legislation exempting non-permanent development from planning control is very long overdue for reform. The fundamental problem is, of course, that the court-led rules that have developed over the years to test for permanency, such as attachment to the ground, do not include any measure for contextual amenity impact, save only that large size may be a factor in the equation.

With regard to the other point you raise, it has long been established that horse keeping is not agriculture within the section 336 definition. This rules out the use of permitted development rights for buildings designed and used for horses. However, the situation is less clear cut in the case of multi-purpose buildings which were initially erected for bona fide agricultural purposes but have later been adapted for horses. This situation arose in a 1990 appeal case from Northamptonshire (DCS Number 100-023-281) where enforcement action had been taken against a structure at a farm containing 4 loose boxes. The council alleged that a horse had been kept in one of the boxes. An inspector accepted that the structure had been lawfully erected using agricultural permitted development rights. There had been a reasonable need for the building for housing lambs and calves, and it had been suitably designed for such a purpose. The notice was quashed, the inspector noting that the partial horse use did not affect his conclusion.

I would be interested to hear of reader’s experiences in similar circumstances where enforcement action has been taken against horse use of buildings originally erected using Part 6 rights. GH.

The judgment in Sykes v Secretary of State for the Environment [1981] held that if horses were simply turned out on land with a view to feeding them from that land, clearly it was in use for grazing. It distinguished between horse grazing, which may be carried out without a material change of use of agricultural land, and horse keeping which would be a change of use. In the case of impermanent structures, such as ‘mobile’ field shelters, it has been held in subsequent cases that, not being buildings falling within the definition of development, their use is ancillary to a use for horse grazing. Where a permanent horse building has been erected on an area of land which has been used for horse grazing it would need planning permission as a building operation unless, as you suggest, agricultural permitted development rights could be claimed. However, as soon as a building such as a stable or hay store is commenced, this negates interpretation of the Sykes definition of "agricultural" horse grazing as a casual activity wholly dependent on the amount of grass available. It could then be argued that horses were being kept on that land and that the use of any building erected could not be "reasonably necessary for the purpose of agriculture" as required if Part 6 permitted development rights are to be claimed. However, there remains a difficult legal point of timing to be resolved in that, at the moment of commencement of construction, a horse building may be said to be still within an agricultural unit and thus could lawfully take advantage of permitted development rights. I do not know of a case where the courts, or inspectors at appeal, have had to grapple with this particular point. In conclusion it has to be said that the conditions whereby mere grazing can be demonstrated in the limiting terms of the Sykes judgment are very difficult to show and few have succeeded. GH.

A outbuilding has recently been constructed twenty metres away from a single family dwelling. The site is located within a designated area of outstanding natural beauty (Article 1(5) land). In my opinion the outbuilding falls foul of qualifying criterion f) of Class E, Part 1 of Schedule 2 of the Town and Country Planning (General Development) Order 1995, because it exceeds 10 cubic metres. However, my colleagues feel that there has been a drafting error in the Regulations as  Class A3(a), would appear to allow building up to 50 cubic metres within the residential curtilage of a dwellinghouse located on Article 1(5) land, reducing by however much cubic tolerance has already been used up in enlarging the main dwellinghouse. I am sure this cannot have been the intention as greater control should have been given over the extent of outbuildings in environmentally sensitive areas. JM.

This is a question that has arisen before in Forum. On the face of it the Order at Class A can well be read as saying that a garden building on Article 1(5) land may be permitted development, even if it is greater than the 10 cubic metre limit allowed by class E. My own response to a similar query back in 2002 was to support that interpretation. One can see what those who drafted the Regulations were trying to do in sensitive areas. But they apparently failed to appreciate the anomalous consequence for the control of large garden buildings if only minor dwellinghouse extensions had in fact taken place in the past, or none at all for that matter. Of course, the likely revision of Part 1 of the Order in the coming year should remove this interpretation problem, as the present volumetric approach is apparently to be abandoned. GH.

My authority received an enquiry as to whether planning permission is required for an extension to the rear of an end of terrace property, where to the rear of the garden is a 5m wide strip of land between the boundary fence and a road.  It was advised that planning permission was not required provided that the strip of land intervened.  Following an enforcement complaint legal advice was that the land could not be classed as intervening and planning permission was therefore required. Is there a limit to how wide a strip of land has to be before permission is no longer required, or is it a matter of judgement? Would it make any difference if the land were classed as adopted highway? DG.

The Town and Country Planning (General Development) Order 1995 (GPDO) states that development at a dwellinghouse is not permitted if "the part of the building enlarged, improved or altered would be nearer to any highway which bounds the curtilage of the dwellinghouse than the part of the original dwellinghouse nearest to that highway". A similar restriction exists in respect of Class B roof additions or alterations which are not permitted development if they extend beyond the plane of any existing roof slope which fronts any highway. The GPDO does not assist further in defining the circumstances in which a house may be said to front a highway and, as you say, this is a matter of judgement for the decision maker. However, most inspectors at appeal will take the view that land which forms part of a highway verge must be considered to form part of the highway. Such an area may be quite extensive, as shown in a case from Hemel Hempstead determined in 2001(DCS Number 047-544-426). Here an inspector felt that an 18 to 20 metre deep open area was part of the highway as it was an integral element in the street scene.

Clearly, it will assist a case that land forms part an integral part of a highway, if it forms part of the area formally adopted as a public highway or is maintained by a highway authority at the public expense.  Conversely, if a strip of land has the function of intervening in visual or land-use terms between a highway and a dwellinghouse boundary, then it cannot reasonably be said to be part of the highway. GH.

If the front elevation of a property faces a highway, the permitted development height for a front fence or wall is one metre. However, the sides of the front garden of this property do not face any highway and therefore the permitted development maximum height is 2 metres. But there is a point at which a 2 metre side wall or fence will face the highway where it forms the junction with a 1 metre high front wall or fence.  In this situation it may be that planning permission is technically required as the 1 metre limit is exceeded. Can you clarify this matter? EJ.

The actual wording of Part 2 Class A of the Town and Country Planning (General Permitted Development) Order 1995 refers to the one metre limit as being applicable where the enclosure is "adjacent to a highway".  The situation you pose was closely examined in an appeal decision from north- west London in 2002 (DCS Number 032-593-193). Here enforcement action had been taken against front and side walls to a suburban house. The local authority argued that where a side wall met the pavement it exceeded the permitted one metre height and was therefore unauthorized in its entirety.  An inspector felt that the council’s interpretation would lead to an illogical result which would result in the application of the one metre rule to fences some distance away from a highway. He was also of the opinion that there was nothing in the Order to suggest a complicated interpretation which would require a side wall be reduced for the last two or three metres of its length before reaching the highway.  The inspector’s preference was to interpret the term "adjacent to" to mean not only "close to", but also "alongside". This would allow side walls and fences up to 2 metres to be located at right-angles to a highway and touching it at one point. Such an interpretation, he concluded, would have the advantages of clarity, certainty and simplicity. So far as I am aware the position taken in this case is generally accepted by local authorities. GH


Article 3(6) of the Town and Country Planning (General Permitted Development)  Order 1995 states that "The permission granted by Schedule 2 shall not authorise any development which…creates an obstruction to the view of persons using any highway used by vehicular traffic, so as to be likely to cause danger to such persons."  A side wall or fence could over 1m in height could obscure the view of users of the highway, including pedestrians, of a car emerging from a property. In order to avoid this danger and comply with the Order my advice is that the first 2m back from the highway should be kept to 1m. The reason for this is clearly understood and accepted, and in accord with the national requirements for safe access set down in Places, Streets and Movement. PE.

Further Response

In my experience, many local authorities interpret the word "adjacent" in accordance with PE’s standard that permitted development side boundary fences must not exceed 1m high for a distance of one fence panel from the highway (about 2m). This is a convenient rule of thumb, and in practice, it is often quite easy to persuade someone who has erected a 2m high fence at right angles to the highway, to attend to the end panel only by removing or reducing in height. However, even this rule of thumb may be amended by Article 3(6), since on some sites, such as in a hilly location, even a fence only 1m in height can obstruct visibility, and thus fall foul of this condition.

Of course, in other cases, where there are no accesses in the vicinity of a proposed fence, any reduction in height could not be justified in the interests of highway or pedestrian safety. While on this subject it is of interest that the height limit favoured by highway engineers, is lower, at 0.9m. So, if part 2 of the GPDO were ever to be reformed, this would be the ideal height to be specified adjacent to a highway. PL.

A farming client wishes to import inert subsoil from local construction activities to fill a bowl in a field to enable a more workable piece of land for crop production. The fill area is 0.85ha and will involve about 1500 full lorry loads. If the subsoil is defined as waste material Part 6 A2.(2)(c) of the Town and Country Planning (General Development) Order 1995 would seem to permit the work subject to the prior approval of the local authority, even though "waste material" imported from elsewhere for deposit is limited at A2.(1)(c) to uses in building works and hardstandings. Can my client take advantage of the apparent anomaly in the Order or is planning permission required? DG.

The Order permits works at farms over 5ha which are reasonably necessary for the purposes of agriculture. This includes engineering operations such as infilling and is subject to the condition that waste materials shall not be brought on to the land from elsewhere for deposit except for use in buildings or hard surfaces. The Order then goes on to require that where the deposit of waste material exceeds 0.5ha, as in your case, it shall be subject to the prior notification procedure. I can only assume that the reference is to waste material sourced from the holding itself, say rubble from demolished buildings. In your case I am reasonably sure that planning permission would be required for your client’s works. Have any readers any other interpretation? GH.


I often have to pick my way through the extraordinary complexities that our legislators have knitted together to permit certain operations at farms, and control others. I agree that the GPDO allows the deposit of waste material on farm holdings over 5ha provided it is for a bona fide agricultural purpose, but only if no waste is brought in from outside - except where required for use in the foundations of buildings or hardstandings. Almost unbelievably ‘waste’ is not defined in the Order. However, this right is conditional upon the prior notification procedure, when over the course of time the total area involved in various filling and extraction activities over the whole farm unit has exceeded 0.5ha. This ponderous construction raises further  ambiguities, as Professor Malcolm Grant points out in his book Permitted Development. ZN.

It should be noted that the 0.5ha area stated is the area of the proposed works when added together with the aggregate of the areas of all other excavations within the unit which have not been filled and of all other parts of the unit on or under which waste has been deposited and has not been removed. This is found at Part 6 paragraph D4 of the Order. However, no time limit is mentioned in the GPDO over which the aggregate area is calculated. This area limit was only introduced by amendments to the previous GPDO in 1992, so is it reasonable to assume that deposits of waste etc before that date do not come into the aggregate? Other areas, such as that of buildings, are subject to two year aggregation only. My local authority is arguing that any tracks or hardstandings on a farm of whatever date shall be included, which in effect would stop most farmers in the country from using this permitted development right. What are the views of others on the period to be considered? MC.

Further response

Waste importation on farms generally comprises construction and demolition (C&D) materials, often including a variety of questionable items.  Para A.2 (1) (c) of the GPDO excludes 'waste materials' from being imported from elsewhere for deposit except for hardstandings and foundations for buildings, inferring a limitation of this to hardcore rather than soil. This paragraph comes before the poorly worded paragraphs A.2 (2) (c) and D.4 relating to the cumulative threshold of 0.5ha, and we have therefore regarded general landfill and landraising as falling outside the remit of permitted development. This makes sense since such infilling alters landscapes and has a high potential for environmental harm. A Waste Management Licence exemption from the Environment Agency is primarily concerned with pollution, giving less weight to other considerations.   Without adequate control of soil importation, the alternative would be a tipping free-for-all without paying landfill tax.  This is now more relevant since farmers can no longer freely bury or burn their own waste. Para D.4 is, in my view, complete nonsense.  Not only is there no indication of the timescale for aggregation of agricultural earthmoving operations on farms, it would be virtually impossible to assess actual cumulative areas and is therefore unenforceable.  Attempted explanations to farmers making enquiries are usually greeted with stunned silence.  Review of this part of the GPDO is long overdue, including terminology, yet agricultural and C&D waste rarely signify in waste management strategies. DK.

I am dealing with an enforcement investigation into whether a new timber lodge 10m from the rear of a rural house requires planning permission. The accommodation is occupied by the owner’s parents who were previously housed in a caravan in the front garden, when the facilities of the house were used on a day-to-day basis. This was deemed to be ‘incidental to the enjoyment of the dwellinghouse’. The present lodge can be transported in two pieces and therefore complies with the definition in the Caravan Sites Act 1968. However, it is arguable whether the lodge is, in fact, within the residential curtilage of the main house. Additionally the lodge is separated from the house by a picket fence, it has its own council tax banding and, so far as I am aware, water and electricity supply are separately metered. There is only one access to the site and both buildings share it.  Can you comment on whether the lodge is an independent unit which could be successfully enforced against? DU.

Enforcement cases of this kind raise a complexity of issues. The first of these is the need to establish whether the structure that has been placed on the land is a building operation or not. As has been debated in Forum before, the mere fact that a structure is termed a caravan using the criteria cited in the 1968 Act, may not necessarily mean that it is not a building operation for the purposes of the Town and Country Planning Act 1990. In the case of the ‘lodge’ type of accommodation you mention it may well be that its supports and service connections give it sufficient characteristics of permanency for permission to be required . For instance, in a 2007 appeal case from the West Midlands (DCS Number 100-050-239) an inspector found that rear garden parent’s accommodation was a ‘mobile home installed as a structure’, where specially constructed supports or foundations had been constructed and plumbing and sewerage systems installed.

The main matter to be resolved is, of course, whether a separate residence has been established on the land resulting in the creation of a new planning unit requiring planning permission. In the case you describe many of the indicators that the accommodation is separate, and does not rely on the main house, seem to be in place. Its curtilage has been defined and service connections are separate, even though access is shared. Such a ‘lodge’ building is certain to provide all the necessary domestic facilities enabling it used independently. The lifestyle question, namely how the accommodation is actually used, is also part of the matrix of considerations that may arise in evidence. For example, in the appeal case already cited, the inspector noted that the parents concerned always slept in the accommodation, used the bathroom and toilet, rested in the unit in the afternoons, and took some meals there. This led him to believe that a separate dwelling s not ancillary to the main house had been created..

The final consideration concerns the input of the Town and Country Planning (General Permitted Development) Order 1995.  If the lodge is deemed to be a building, and provided it is within the curtilage of the dwelling house, as a ‘incidental’ garden structure it is likely to fall within Part 1 Class E as permitted development. However, according to the government’s controversial interpretation of the Order this does not apply if the building is immediately used for primary living accommodation. 

In summary, in order for your council’s potential enforcement to be successful and survive the likely appeal, it does need to assess very carefully whether it has sufficient hard evidence to justify an allegation of an unauthorized building and/or a material change of use. GH

Can you advise whether a planning authority is correct in stating that an extension to an agricultural or forestry building which was granted planning permission, can only be dealt with by a further application for planning permission rather than by the prior notification procedure. Also whether a planning authority is entitled to place conditions on the use rather than on matters of siting and design. BL.

I can find nothing in Part 6 of the Town and Country Planning (General Development) Order 1995 to suggest that the prior notification procedure is not applicable just because the building to be extended originally required conventional planning permission.  It would be possible for a condition to have been applied to such a permission taking away rights to the prior notification procedure for future extensions, but I envisage that it would have to be carefully justified in order to survive an appeal. Government advice has always been that the matters which may be controlled using the prior notification procedure do not extend to the principle of the development, only its effect upon landscape strictly in terms of siting and design. It follows that conditions applied should be similarly confined and not seek to control matters such as access or residential amenity. GH.

The guidance at Annex E to PPG7 on permitted development rights for agricultural or forestry developments refers to the determination procedure for prior notification cases and states that in such cases  the principle of the development is not at issue but that local authorities may concern themselves with matters of siting, design and appearance. My council takes advice from the County Council Land Agent who routinely applies this guidance to all detailed applications for agricultural buildings. However, it has been suggested that the guidance at Annex E is not relevant to full applications, the implication of which could be that in such cases a less rigorous assessment is possible. I feel that this would be perverse, and seek your view.

A farm building, in order for the prior notification scheme to be brought into play, must have already satisfied certain basic criteria to qualify as permitted development i.e. that the building is at an existing ongoing agricultural holding and is reasonably necessary for the purposes of agriculture within that unit. In other cases, where express permission is required for an agricultural building at the outset, say because there is no existing agricultural unit, there is no specific guidance in PPG7 as to the material considerations that should be applied. Therefore where there are amenity, highway or landscape objections to such an agricultural building an assessment has to be made in the conventional way as to whether the need case for the development outweighs any harm to planning policies.  Depending on the development plan policies operative in a particular area it is possible, as you state, that a proposal for an agricultural building could have fewer hoops to jump through if it did not fall to be dealt with under the prior notification procedure. I agree that this is perverse.

A telecommunications operator has notified my authority of a proposed installation. Since this was permitted development requiring prior approval, only its siting and external appearance were assessed. While I was told that we could not impose a condition in such circumstances, I later discovered that there is a case where this was done on appeal. Is an authority entitled to attach conditions to a prior approval after all?

I cannot find any such precedent. This possibility is not mentioned in Annex 1 of PPG8, which sets out advice on the prior approval procedures, the ODPM’s best practice code on mobile phone network development or Circular 11/95. PPG8 explains that authorities may wish to discuss modifications to a proposed development with the developer to mitigate concerns and that development must be carried out in accordance with the details submitted with the application "or as otherwise agreed in writing by the authority". I take this to cover situations where an operator changes the proposed development to overcome concerns, since a condition imposed unilaterally by the authority would seem to fall outside the scope of the phrase. I cannot find any legitimate basis for imposing conditions on such approvals.


My authority has had a number of appeal decisions where such conditions have been applied, including one requiring the colour of the mast to be agreed.

In a recent decision from London (DCS No: 100042513) an inspector granted approval for a mast subject to a condition requiring it to be installed in accordance with a method statement to minimise disruption to its surroundings to be agreed in writing with the local planning authority.

Our client wishes to demolish a former school and a Scottish council has requested a prior notification application. The building is not listed or within a conservation area and does not appear to be in any of the other categories listed in the Town and Country Planning (Demolition which is not Development) (Scotland) Direction 2001 as requiring a prior notification. Can you advise, please? REL.

The only relevant category in the 2001 Direction is that covering dwellinghouses, buildings containing flats and buildings having a mutual wall with, or having a main wall adjoining the main wall of a dwellinghouse or building containing flats. Unless the school has a party wall with or adjoins a residential building a prior notification of demolition would not seem to be required. If prior notification is needed in Scotland, as in England, it cannot be refused. A council may only control the method of demolition and site restoration. JH.

My authority issued a lawful development certificate under section 192 of the Town and Country Planning Act 1990 for a proposed dormer extension to an empty house. At the same time that the dormer was constructed, internal partitions and other works were carried out to facilitate the building's subdivision into flats, although these were not completed. The property was then used as a house in multiple occupation (HMO). A planning application has now been submitted to convert the house to two flats. Since the property was not occupied as a single dwelling after the dormer extension was built, could it be argued that the dormer was not permitted development, especially in view of the other internal works?

Neither flats nor HMOs enjoy permitted development rights. The point at which a building ceases to be a single dwellinghouse is a matter of fact and degree. The fact that the dwelling was not occupied when the works were carried out is not in itself determinative. Until the existing use is abandoned or a new use is instituted, the building's lawful use as a single dwellinghouse will continue. Therefore, if the dormer was built before the other works, there is little doubt that it would have been permitted development. The term "dwellinghouse" is not defined in the General Permitted Development Order 1995 or the Town and Country Planning Act 1990. However, advice in Circular 10/97, which draws on the approach taken in Gravesham Borough Council v Secretary of State for the Environment and O'Brien [1982], sets out the criteria for determining the use of a building as a single dwellinghouse. These include the physical condition of the premises and the manner of its use. So if the building was neither occupied as a single dwellinghouse nor recognisable as such as a result of the internal adaptations, any dormer erected at the same time that those works were carried out would not be permitted by the Order.

If an owner started construction of a swimming pool that was allowed under the old permitted development rights but does not comply with the revised rights that came into force on the 1 October, will he require planning permission to finish the project? SL.

No, the "planning permission" granted and commenced under the former General Permitted Development Order provisions would be treated in a similar way to work commenced before the expiry of the three-year period of a conventional planning permission; it keeps the permission "alive". If this were not the case, the outcome could be very inequitable as someone could have spent a large sum of money on building something they might not then be able to complete. JH.


This has been the subject of some discussion amongst officers in this authority. You have stated that works once begun may be continued. I would be grateful to know the legal basis for this. The new order is made under sections 59, 60 and 61 of the Town and Country Planning Act 1990 which give the Secretary of State power to make GPDOs and also section 333(7) which deals with revocation.  The effect of the new order seems to be that the relevant part of the preceding one is revoked and replaced by the new provisions.  If this is so there is no provision of which I am aware which allows partially implemented planning permissions to be completed. The normal position with revoked planning permissions is that partially implemented ones cannot be continued but works carried to the date of revocation can be retained – see section 97(3) of the 1990 Act.  This and the immediately following sections do not seem to be particularly apt to the revocation of GPDO permissions by the Secretary of State, under section 333(7), but the principle may be similar.  This is borne out by section 108 which expressly provides for compensation for applications made within 12 months of the cessation of permitted development and which incorporates section 107 which refers, inter alia, to compensation for abortive works. GC.

Further Response

Another reader has expressed similar views. The lead case on this issue is R.J. Williams Le Roi v SoS & Another [1993] and this subject is discussed in some detail in Section 4.343 of Development Control Practice. The law seems quite clear in supporting the interpretation I gave. JH.

Under the General Permitted Development Order amendment effective from 1 October, if the principal elevation is staggered elevation, do we assume any extension forward of the part set back needs permission?  SG.

The relevant wording is, "Development is not permitted…if…the enlarged dwellinghouse would extend beyond a wall which fronts a highway, and forms…the principal elevation…of the original dwellinghouse". Though this wording is, like many other parts of the amendment, not very clear, it would seem to mean extensions such as you describe require permission in contrast to the situation with the previous provisions.

What is the position regarding Certificates of Lawfulness for Existing Use or Development for domestic extensions, etc built before 1 October when the General Permitted Development Order amendment became effective?  If the development was carried out under the old rules and completed before 1st October, will an application for a Certificate of Existing Lawful Development be judged under the new or the old Order? AR.

If development is commenced under the old regime and is lawful, the change in legislation would not affect that status. Thus the application should be determined on the basis of the previous rules. Part of the council’s assessment should, however, be to verify that the work was commenced before 1 October. JH.

Would a householder require permission under the new provisions for a first-floor side extension above an existing single-storey attached garage if the garage is part of the original dwellinghouse? EH.

A1 (h) of the General Permitted Development Order Amendment restricts extensions going beyond a side wall.  The house you describe has two side walls, the main one and that of the garage. It would project beyond the side wall of the main house and exceed 4 metres in height, so it would require permission. JH.

A client started exercising permitted development rights to form an access to an unclassified road, which meant he had to knock a wall down. He made enough space for a car, but it was his intention to make it somewhat wider.  He has taken some time to do this and during the time the area was made a conservation area.  Does he require conservation area consent to continue demolishing down the wall? SC.

The situation is analogous to commencing building an extension prior to the General Permitted Development Order Amendment came into effect on 1 October which was raised in Forum on 3 and 24 October 2008. Section 4.343 of Development Control Practice discusses this issue in some detail and I would not consider he requires conservation area consent. It would, however, be advisable to discuss this with the planning authority before continuing work to ensure they are satisfied with the situation to avoid the possibility of enforcement action being taken. JH.

Many planning permissions issued by this authority before 1995 removed permitted development rights for dwellings using conditions referring to the General Permitted Development Order 1988 as amended. They did not include reference to any subsequent order revoking and re-enacting with or without modification, as set out in the model conditions in Circular 11/95. Are such conditions enforceable now? JC.

Such conditions normally comprise a qualifying clause beginning, "Notwithstanding the provisions of" or similar, followed by a requirement such as, "No extensions shall be added to the proposed dwelling unless planning permission is obtained for them". If the qualifying clause were to be deleted altogether, the sentence would still make sense and the condition would be enforceable. Thus, I would suggest, even if the reference to subsequent orders is omitted, the condition would still "bite". JH.

What is the situation if an authority receives an application for what is actually permitted development? Are there any adverse practical, procedural or legal consequences if permission is granted? RT.

The council is not empowered to grant a certificate of lawful development in such circumstances. It can only seek the withdrawal of the application or determine it. In the case of Newbury District Council v Secretary of State for the Environment 1981, it was held the existence of a permission did not debar a landowner from asserting that permission was not required. Thus any conditions that might be imposed would be of no practical effect unless the relevant permitted development right were withdrawn before the permission expired, in which case the landowner could still implement the proposal relying on the permission. JH.

Given that most councils would consider excavation of soil 1m deep or more as engineering works requiring planning permission, if a householder wishes to build an extension under permitted development involving digging out banking to similar depths, would that mean planning permission is required? BP

Building an extension on level ground may require foundations 3 metres deep, but assuming the limitations in the General Permitted Development Order 1995 (as amended) were met they would be  no doubt it was permitted development. Thus, generally building into banking would not change the situation, though if the excavations were excessively deep, it might then be considered planning permission would be required. JH.

The recent General Permitted Development Order amendments require some windows to be ‘obscure-glazed’.  I have a case where a window has been fitted with glass the manufacturer calls ‘level 1’ obscure glazing but it allows direct overlooking of a neighbouring property.  Is there any case law or definition of what can be classed as obscure glazing? BK.

There is a recognised scale devised  by Pilkingtons grading obscure glazing from 1 (least obscure) to 5 (most obscure) – see When imposing an obscure glazing condition, some authorities specify a minimum on this scale, but as you point out the General Permitted Development Order does not specify a minimum. If the glazing failed to meet the level 1 standard, you could reasonably argue it was not obscure glazed, but if it meets the lowest standard on this generally recognised scale, such an argument is not likely to succeed. JH.

Is cladding or rendering a dwelling still permitted development following last October’s amendment to the General Permitted Development Order 1995?  If so what is the view if an extension is approved subject to a 'matching existing materials' condition and then the owner changes the external finish (say from brick to render) prior to implementing the permission? Would finishing the extension in render remain in compliance with the condition? SM.

A.2(a) of the amendment states cladding, rendering, etc is not permitted development on article 1(5) land, but A.3(a) imposes a condition that to be permitted development exterior works should be of materials of similar appearance to those of the existing dwelling. I would interpret this to mean that an existing dwelling which is wholly brick cannot be clad or rendered as that would introduce a new external finish. On the other hand, on a dwelling that is partially clad or rendered the extent of this could be increased, providing, of course, it is a similar finish.

It would be unusual for a dwelling to be clad and then later extended as it is generally cost effective to carry out all building work at once. If this did happen, however, it might not be expedient to enforce, particularly if the materials used on the extension matched those on nearby houses. Nevertheless, the scenario might occur where a house which is, , brick and render, gets permission for an extension, is then fully rendered and the extension is built in brick. In such circumstances I would consider a reference to matching "existing materials" to refer to what existed immediately before the extension was built, so it would be possible to take enforcement action if considered appropriate. Conversely, if the house when enlarged was fully rendered and the extension was finished in render, there would be no breach of planning control. JH.

Section E.3 of last October’s General Permitted Development Order amendment refers to "land between a wall forming a side elevation of the dwellinghouse and boundary of the curtilage of the dwellinghouse". I interpret this to mean you cannot place buildings, enclosures etc. between a side wall and curtilage boundary on article 1(5) land. A local authority thinks the area within which the restriction occurs continues along the plane of the wall, restricting development elsewhere in the curtilage that is not immediately alongside the house. This is not what the order says, is it? MH.

Similar wording is used in section F.1(a) of the amendment in relation to requiring porous hardstanding in front gardens and in that context it would seem it should refer to the whole front garden, not just the area immediately in front of the house as a provision requiring porous hardstanding in part of but not all of a front garden would be very illogical. In the case of E.3 buildings, etc, whilst if they are in a rear garden they would not be very prominent, they would nevertheless often be visible from in front of the house. Thus, there is some logic in the authority’s interpretation. Either interpretation would be possible, though personally I have a preference for yours. I would suggest you make a certificate of lawful development application and, if it is refused, lodge an appeal to clarify this point. We would, of course, be interested to hear the outcome of any appeal. JH.

If someone has a house with an L-shaped frontage, is planning permission required to infill the "L" under the recent General Permitted Development Order Amendment? FD.

This query raises similar issues to infilling the "L" at the rear of a house which was considered in the column on 28 November last year and 9 January this year. The relevant wording in the amendment for front extensions is that they are not permitted if "the enlarged part of the dwellinghouse would extend beyond a wall which fronts a highway and forms either the principal elevation or a side elevation of the original dwellinghouse". For rear extensions they are not permitted if "the enlarged part of the dwellinghouse would have a single storey and extend beyond the rear wall of the original dwellinghouse by more than 4 metres in the case of a detached dwellinghouse, or 3 metres in the case of any other dwellinghouse". Both provisions use similar wording is used.

In its document giving informal views on the amendment available on the Planning Portal website, in relation to rear extensions to an L-shaped house the Department of Communities and Local Government advises, "The relevant consideration here is the part of the wall that is being extended from. Therefore where there is an original rear addition/outrigger there will be more than one original rear wall". Because the provisions for front and rear walls are worded virtually identically, it would seem that infilling an "L" at the front of a house would also require permission. As far as I am aware, however, there has not been any appeal decision to confirm this interpretation. JH. 


In the first new query in your 3 July edition you address the issue of L shaped properties and highlight the Department of Communities and Local Government advice that a property may have more than one original rear wall for the purposes of the recently amended General Permitted Development Order.  Such a property would, by the same logic, have more than one side wall.  Would infilling the L at the rear of the property (extending beyond one of those side walls) therefore be limited to single storey and be subject to the other limitations under A.1 (h),  notwithstanding the fact that a two storey extension  would satisfy the provisions of  A.1 (f)? MB.

Further Response

Fortunately, this scenario will be fairly rare as most L-shaped houses in England are relatively narrow Victorian ones and provision A.1 (g) effectively means two-storey extensions can only be built as permitted development on houses with plots of around 7 metres width or more.

This is, of course, another example of ambiguity in the amendment because whoever drafted it failed to realise that not all houses are conveniently rectangular. Whilst I cannot cite appeal cases, etc to support my view, I would suggest that if the government considers extensions infilling an "L" to be rear extensions, it would not be appropriate to consider them as side extensions too, i.e. two-storey extensions can be permitted development if they are the requisite distance from the boundary. JH. 

Further Response

There is an appeal case concerning a certificate of lawfulness in Hertfordshire (DCS reference: 100-062-040) that indicates infilling an "L" at the rear of a house in a conservation area would be both a rear and side extension. MP.

Further Response

Thank you for drawing this appeal to my attention. What I was suggesting did seem a reasonably logical position, but clearly the inspector determining this appeal has taken a different view. As readers will be aware, last year’s ill-considered amendment to the General Permitted Development Order 1995 has created many problems of interpretation which are causing tremendous difficulties for practitioners. If further appeals follow this inspector’s view then this issue will have been clarified, but it would have been better if the legislation had been clear at the outset. JH.

Further Response

I have read the Hertfordshire decision. In my view it is flawed - the Inspector seems to have formed the view that because the extension cannot be considered under criteria for either rear or side extensions, then it cannot be permitted development. However, the starting point is that all extensions are permitted unless caught by the relevant exclusions. In this case, if, as the Inspector suggests, the extension is not caught by either rear or side extension criteria then subject to compliance with the general criteria for permitted development it must be permitted. This is yet another loophole in the revisions to the General Permitted Development Order. RB.

Further Response

The difficulty in interpreting last year’s General Permitted Development Order Amendments is a regular theme in this column and this is yet another example of the problems it raises. JH.

Further Response

In DC Forum on 3 July 2009 you discussed infilling the rear of an L-shaped dwelling and suggested that, based on the Department of Communities and Local Government advice on the Planning Portal, there would be more than one original rear wall.  This seems contrary to the wording of last year’s General Permitted Development Order Amendment which uses 'the' rear wall implying just one. At that time you said that you were not aware of any appeal decisions confirming the interpretation.  Have there been any appeals clarifying this? 

Further Response

There has been an appeal in London (DCP No 100-064-218). Here the extension projected 3 metres from the rearmost wall, but also included an element to the side, making the house a C- or U-shape. Applying the Portal advice, the Inspector dismissed the appeal. JH.

I have built an extension to my house which I have now realised is slightly longer than the permitted development tolerances would allow. I have proposed reducing its length so it becomes permitted development, but the council says that does not make it lawful. Can you advise? PT.

This issue has been considered in a recent appeal in north London (DCS reference 100 063 014).  Article 3(5) of the General Permitted Development Order 1995 states permitted development rights do not apply "if in the case of a permission granted in connection with an existing building, the building operations involved in the construction of that building are unlawful". The construction of the extension, as it exceeded the permitted development tolerances, was unlawful, so reducing its size cannot consequently make it permitted development. Thus, you cannot just reduce the size of your extension.

Having said that, in dealing with such matters planning authorities need to be aware that, if an enforcement notice is served the householder can demolish the extension and then build what is permitted development. In view of this fallback situation, most would not consider it expedient to enforce if the householder were willing to cut back an extension so it became permitted development. Within this context it would be sensible for you to negotiate with your council and agree an acceptable compromise. In the case referred to above the inspector did uphold the enforcement notice requiring the demolition of the extension, but he extended the period for compliance as he considered a suitable compromise could be negotiated between the parties. JH.

An application for a first-floor extension to a house in the countryside to be built over an existing flat roofed extension was refused as it would add more than 30% to the floor area of the house as it existed in 1948. Before submission, a council officer advised the house could have extensions under last year’s General Permitted Development Order amendment on the opposite side and to the rear without permission which would be much larger than the submitted proposal.  Why is this disparity not taken in account in determining the application?  The client wants a modest extension which integrates better with the existing house’s layout. GM

The issue of fallback rights in relation to permitted development is considered in section 4.346 of Development Control Practice. Provided there is a reasonable prospect of the applicant using such rights, they should be taken into consideration in determining applications. In your case it would seem appropriate to negotiate with the council and see if they would be willing to allow the scheme with either a condition or a planning obligation taking away the permitted development rights. Having said that, foregoing rights to enlarge the property further could affect its value and your client needs to be aware of the implications of this. JH

A resident has built an outbuilding alongside his house. It has a mansard-style roof, i.e. with very steeply sloping sides with a much more shallowly sloping top coming to a ridge and is 3.95 metres high. It meets all other permitted development criteria. Do you consider it requires planning permission? PH.

Under the provisions of part E.1(d) of last year’s General Permitted Development Order Amendment, only outbuildings with "dual-pitched" roofs can be built to a height of 4 metres as permitted development. I would not consider this to be a dual-pitched roof as it has four planes. Furthermore, such a roof is likely to have more impact upon neighbours. In assessing whether to take enforcement action, you should bear in mind that a similar building could be built with a conventional dual-pitched roof as permitted development in its place. Thus, generally enforcement action should only be taken if the form of the roof means the development is significantly worse than the fallback alternative, e.g. a neighbouring property is more adversely affected or the style of roof is out-of-character with the area. JH.


On 7th August 2009 you dealt with a question about a 3.95m outbuilding you described as having a "mansard –style roof". Your description of it," with very steeply sloping sides with a much more shallowly sloping top coming to a ridge" would suggest this is actually a gambrel roof. A website,, cites a gambrel roof as being a dual-pitched roof. Do you stick to your opinion this would not be permitted development? AM.

Further Response

I was not familiar with the term "gambrel roof" when I answered the original query, but it seems the term has different meanings in Britain and America. In Britain the term means a half-hipped roof, but the roof I described would seem to meet the American definition of a gambrel roof. The website you refer to is American and therefore would have limited weight in the interpretation of English legislation. I still do not consider the roof to be dual-pitched but it is just possible an Inspector in a planning appeal could take a different view as this is an issue of interpretation. JH. 

The planning authority involved has now sent a copy of the decision for an enforcement appeal relating to this building and the inspector dismissed the appeal on ground (c) (and other grounds) commenting it clearly was not a dual-pitched roof as there were two distinct roof planes set at different angles (DCS no: 100-069-596). JH.

The General Permitted Development Order (Amendment) (England) Order 2008 relating to microgeneration does not cover domestic wind turbines. Until legislation is introduced to address this could you advise which classes a domestic wind turbine attached to a house roof or a wall or a freestanding one should be considered under? Planning Portal advice states that consent will normally be required but does not state why. DG.

Classes A, B and E respectively of the schedule of the General Permitted Development (Amendment) (No 2) (England) Order 2008 would be the obvious places to start looking to see if domestic turbines require planning permission and clearly any assessment would need to be made against all the criteria set out. The requirement for materials to be of similar appearance would preclude some turbines from falling within classes A and B. Class E permits "buildings" and article 1 of the General Permitted Development Order 1995 indicates this term includes "any structure or erection" but not "plant and machinery". Whilst some might argue that a wind turbine is "plant and machinery", the consensus view seems to be that it is not the case. Class E turbines are restricted to a height of 3 metres, however, which in many locations would not be sufficiently high to make installing one worthwhile. JH. 

On 29 May I submitted a prior approval application for a barn. The authority advised a site plan discrepancy made it invalid. On 10 June an amended valied application was registered, the 28-day period expiring on 8 July. On 10 July the authority’s website had no entry saying the application had been determined so I advised the applicant prior approval was not required and he ordered the barn. Later that day a "decision letter" arrived referring to the 29 May application and claiming the proposal was not permitted development because it was not reasonably necessary for agricultural purposes (I had given evidence why the barn was required).  Has the authority validly determined the application? The applicant needs the barn for his forthcoming crop.  JA

Though the decision refers to 29 May, it is generally accepted that periods for determining planning applications, prior approvals, etc start when the application is valid and you did not argue the initial invalidity. Thus 8 July would be the latest date for a decision when I gather one was made. Class 6 of schedule 2 of the General Permitted Development Order 1995 says for prior determinations the development shall not be begun before the occurrence of various alternatives including 28 days expiring "without the local planning authority making any determination as to whether such approval is required or notifying the applicant of their determination". As the decision was made within 28 days and promptly dispatched, it would be difficult to argue it was out-of-time. The lack of a decision on the website cannot be taken as determinative as it could take a few days to update a website.

Regarding the council’s view that the barn is not permitted development, Planning Policy Guidance Note 7 Annex E advises authorities should verify a prior notification proposal is permitted development. In an appeal relating to agricultural development in Warwickshire (DCS no: 100-058-881), however, an inspector commented, "The advice in Annex E of PPS7 (sic) is not legislation and cannot override or supplement the statutory provisions of the prior notification procedure. The procedure does not require the local planning authority to determine whether or not the permitted development rights exist in the first place. The Act contains other provisions where such a determination can be made." He also considered that if an authority incorrectly indicates a proposal is not permitted development it can be implemented, a view endorsed by another inspector in a case in Yorkshire (DCS no: 100-056-509).

The options in this complicated scenario are a planning application, a certificate of lawful development application or building the barn and seeing if enforcement follows. I favour either or both the latter options. Whilst building when a project’s planning status is unclear is obviously risky, in this instance its early use for crop storage would strengthen the case it is necessary for agriculture. I would be interested to hear the outcome of this. JH. 

Do any readers have experience of 'care farming' or similar proposals, comprising a combination of agriculture and horticulture with educational and therapeutic uses?  A social green belt enterprise seeks new semi-permanent buildings (e.g. yurts) for training, storage etc. on a derelict site recently brought back into agricultural use.  Would permitted development rights apply given the mixed nature of the use?  If permission is needed, have other such proposals received favourable treatment in green belt locations? PM.

The questioner seeks others’ experiences and I would urge any readers who can comment to do so. Regarding your query about permitted development rights, an assessment would have to be made as a matter of fact and degree whether the use was still agricultural or composite. If a farmer has very occasional educational visits, the use would be still agricultural. On the other hand, if he has regular coach parties, etc and there is a classroom block, the use would probably be composite and these rights would not apply. An appeal decision in Shropshire relating to permaculture activities (DCP no: 100-059-638) is worth studying, especially as it refers to other relevant appeal decisions. In that instance educational courses were provided, but the inspector did not consider these were of a scale that took the use outside agriculture.

In relation to green belt issues, unless it were to be considered recreation, such development would be inappropriate. This does, however, seem a somewhat literal interpretation of the planning policy guidance note 2 advice. Such a use has to be in a rural location and preferably close to urban areas. Thus, provided such a proposal did not unduly harm the openness of an area, it might be justified as very special circumstances. JH. 

A semi-detached bungalow was demolished without the necessary prior notification, the remaining bungalow being left damaged and leaking. What enforcement action is possible and appropriate? Circular 10/95 advises that where an enforcement notice is issued, it may require the construction of a replacement building ‘as similar as possible' to the demolished building.  I am not sure that an enforcement notice could require, for example, remediation of the neighbour's walls and gutters as that would mean the perpetrator doing work to someone else’s property and the neighbour might not allow access. Also, if the remediation fails later, the council might be liable for having required the works.  There are no strong planning grounds for seeking the bungalow’s reconstruction.  Can remedial works to the remaining bungalow be required by an enforcement notice?  EM.

I presume the person who demolished the bungalow did some work on/damage to the adjoining one. An enforcement notice requiring such work on or damage to the neighbour to be rectified would have to be served on the neighbour and they would be committing an offence if it were not complied with, though they could probably claim the cost of complying from the adjoining owner. Provided it just related to work on his side of the party wall, there would not be a problem serving a "make good" enforcement notice on the person who demolished the bungalow. If the specified work accords with normal practice, I would not consider the council would be liable for future problems. In this situation you could consider an enforcement notice with the alternatives of making good the party wall, etc or rebuilding the bungalow. JH. 


Does not the neighbour have access to redress under the Party Wall etc Act 1996? The planning system does not exist to protect the interests of one person against another. DE.

Further Response

EM appears concerned whether or not enforcement action could be taken to secure the rebuilding of one half of a pair of semi detached bungalows, demolished without permission, but goes on to say that there are no strong grounds for this. The answer is therefore simple!  Forget about it! SC.

Further Response

Whether Party Wall Act notification would be necessary would depend on exactly what work was carried out, but DE makes a good point that it is important to differentiate between public and private issues and an enforcement notice should only be served if there is a public benefit in doing so, e.g. having an unsightly exposed gable treated. Within that context, if EM’s authority decides there would be no public benefit in serving an enforcement notice, as SC suggests, it would not be expedient to serve one. JH.

My local authority has refused a lawful development certificate for a 3-metre rear extension to a rendered house in a conservation area. The extension would be rendered so as to be "of a similar appearance" to the dwelling to comply with requirement A.3(a) of the amended General Permitted Development Order 1995. The application was refused because it does not comply with A.2(a) because the extension is rendered (not permitted in a conservation area). The authority concedes a planning application is likely to be granted, but the Order is surely designed to relieve the planning system of uncontentious applications. Has the authority any discretion on this? AR.

The A.2(a) restriction on article 1(5) land refers to "the cladding of any part of the exterior of the dwellinghouse". I would interpret this to refer to the cladding of an existing dwellinghouse and not be intended to prevent the scenario you describe, a rendered extension to a rendered house, though it would have been preferable if the Order had said "the exterior of an existing dwellinghouse". Thus, it is possible an appeal against the refusal would be successful and, if you appeal, we would be interested in the outcome. On the other hand, if your client is keen for an early start on the extension, it might be simpler to make a planning application. JH.

Planning Policy Guidance Note 2 restricts dwelling extensions in the green belt to protect its openness, but last year’s General Permitted Development Order Amendment allows substantial additional extensions, after an application for extension has been allowed, so a property could be vastly over-extended. In an appeal decision in Staffordshire that has come to my attention (DCS No 100-064-270), an inspector accepted the need to remove permitted development rights by condition when allowing an extension to a green belt dwelling. In that case, removing the rights was supported by supplementary planning guidance, but the issue is a national one. Although circular 11/95 says that permitted development rights should only be removed exceptionally, do you think a similar condition to the Staffordshire case could be used as a matter of course? MK.

In my experience inspectors are willing to accept conditions removing permitted development rights if there are good reasons for imposing them and they only remove appropriate rights. For instance, in the appeal you quote, the inspector varied the original condition so it only took away rights for extensions and outbuildings, but not other rights. Each case needs to be considered on its own merits. To take an obvious example, if permission is just sought for a porch, it would be inappropriate to take away permitted development rights. In the case you cite, however, the extensions which resulted in the council imposing a condition taking away permitted development rights increased the size of the dwelling by 24% If removing conditions is supported by development plan policy (any such policy should specify the particular types of circumstances in which it would be applied), this of course means an inspector would be more likely to accept it. JH.

Our team has different opinions regarding measuring decking height under the General Permitted Development Order 1995 as amended. Decking can be considered as a raised platform. When the site slopes where should the dimension taken from? Under article 1.(3) a building’s height is measured from the highest part of the adjacent ground. Is this the correct method for decking? MC.

The article1.(3) method of measuring height relates to buildings (and plant and machinery). Though the definition of "building" includes "any structure or erection", I would not consider decking fits this definition. Furthermore, using this method for decking could result in decking which considerably overlooked neighbours on steeply sloping sites, so such an interpretation would seem illogical. Thus, my inclination would be to measure using height above the ground at all points on a slope, but as far as I am aware this issue has not been decided at appeal under the new provisions. JH.


You stated that the word ‘building’ includes any structure or erection.  This is defined in S336 of the Town and Country Planning Act 1990 and in article 1(1) of the General Permitted Development Order 1995.  But you then state that decking would not fit this description.  However, in Skerrits of Nottingham Ltd v Secretary of State for the Environment Transport and the Regions [2000] the Court of Appeal identified three factors as being relevant to the question of what was a "building"; size, permanence and physical attachment.  Surely decking is permanently and physically attached to the ground and so is a structure?

If decking is considered a structure (involving some sort of building operation for its erection), is it permitted development?  The revised General Permitted Development Order excludes raised platforms with a height greater than 300mm from classes A and E. If the platform exceeds 300mm from natural ground level, would it be permitted development? AG.

Further Response

Analysis of appeal decisions indicates decking can be permitted development under classes A, E or F, though if it is raised up significantly it would not fall within class F. Having considered your comments, it would seem that raised up decking would constitute a structure, so its height should be measured from the highest point of adjoining ground level, though on sloping sites this can produce the anomaly that decking could overlook neighbours. Thus, it would only be a "raised platform" if it exceeded 300mm in height if measured in this way. Do any other readers have comments on or experience of this issue? JH. 

The General Permitted Development Order 1995 as amended allows single-storey rear extensions to dwellings of 3 or 4 metres. For a lean-to roofed extension should this measurement be taken strictly to the extreme of any part of the new building i.e. the outside of the overhanging gutter on a projecting fascia or is this measurement considered to be to the line of the wall ignoring the gutter overhang, etc?  We find different authorities have different interpretations. Your response would be appreciated. RH.

Both interpretations are possible. The first is a literal one, whereas the second one is more pragmatic, treating the guttering as de minimis. I personally would prefer the latter, especially as in an appeal in Somerset (DCS No 056-109-344) a finial was not considered part of a roof. As far as I am aware there has not been any appeal decision determining this issue. JH.


I am sure you are right that eaves and gutter overhangs should be ignored. This has been confirmed by two appeal decisions (DCS Nos 100-064-217 and 100-066-450). SI.

Recently permission was granted for the sub-division of a dwellinghouse with an attached granny annexe into two separate dwellinghouses. No conditions were imposed taking away permitted development rights. I recall reading implementing such a permission gives the houses permitted development rights although the original house has already been significantly extended. Can you assist and is there a case where this has been determined? JA.

As an original building is defined as what existed in 1948 or as it was built if it was built subsequently, it would seem that the situation would be the opposite of what you presume. I cannot find a case on this issue pointing either way, however. Can any reader help, please? JH. 

Part of an extension to the side of a house would be permitted development on its own, but the other part is forward of the principal elevation and needs permission.  Is a local authority entitled to exercise control over the whole project, say by stipulating the use of a particular type of roof treatment for both parts of the extension? GH.

If all the work is to be carried out as one project, it must be considered as one entity. Thus, the authority is able to control all aspects of the development. A recent appeal decision which demonstrates this principle is DCS No 100-062-805. JH. 

I have a house with a bay window. To get room to park a car in the front garden, I want to remove the bay and make the front flush using matching materials. I believe this is permitted development, but the council says I require permission as I am materially altering the external appearance of the building. Who is correct? The road is not classified incidentally.  WN.

Provided you are using external materials similar to those of the existing house and the hardstanding is porous, the proposal would be permitted development. In assessing if something requires planning permission it is necessary to decide whether it constitutes development and this alteration would clearly be so as it is a material alteration to the external appearance of the building. The next stage, however, is to consider whether it is permitted development (or a change of use allowed by the Use Classes Order 1987). The council is failing to make this second assessment so not realising your proposal is permitted development. JH. 

The recent General Permitted Development (Amendment) (England) Order 2010 changes the article 4 direction process. Paragraph (2) of article 2 of the amended order replaces articles 4, 5 and 6 of the original order with new articles. Reference to article 4(2) has now been removed. It therefore appears that authorities can no longer make article 4(2) directions. Article 4(1) directions have typically been used up to now to remove permitted development rights from areas rather than individual properties. In contrast article 4(2) directions were used to remove rights from individual properties. Should authorities now use article 4(1) directions in respect of individual dwellings? MP.

The difference between 4(1) and 4(2) directions under the old provisions was that article 4(2) allowed authorities to make certain directions in conservation areas without the Secretary of State’s approval, whereas the Secretary of State had to approve all article 4(1) directions. The difference was not that one covered individual properties and one areas. Under the recent changes, the Secretary of State no longer has to approve article 4 directions, though a copy has to be sent to him.  Instead a procedure is set out for all article 4 directions for authorities to approve their own draft directions in a similar procedure to that used to confirm authorities’ own tree preservation orders. JH.

The October 2008 General Permitted Development Order precludes "raised platforms" from permitted development. I understand this is to avoid overlooking from such structures, usually decking. According to article 1(3) of the "parent" 1995 Order, in measuring height where the ground is not uniform the measurement must be from the highest part of the adjacent ground. Can you confirm therefore that provided any decking immediately next to the house is no more than 300mm high, then no matter how much the land may slope from the house the height at the point furthest away is immaterial? BT.

The article 1(3) rule relates to "buildings, plant and machinery" and the definition of "building" in article 1(1) includes any structure or erection. Much as it might seem anomalous, I would therefore agree your interpretation. JH.

The Land Use Gazetteer advises a holiday home (self catering) falls into a C3 use class. Therefore, I presume if someone wishes to use a dwellinghouse (C3) as a holiday let this would not require permission as long as no more that 6 holidaymakers stay at any time?  Once it is being used as a holiday let would householder permitted development rights apply?  EA

Second homes and homes let as self-catering holiday homes all fall within the C3 Use Class (see R. v Tunbridge Wells Borough Council ex parte Blue Boys Developments et al 1989 and Moore v Secretary of State for the Environment  and Another 1998). This is why in some tourist areas second and holiday home demand results in a shortage of homes for local people so some authorities have policies restricting occupancy of new houses to local residents. A house used for holiday letting would enjoy normal domestic permitted development rights. JH.

Do static caravans have permitted development rights? I am asking this as a court case has come to my attention (Green v Secretary of State for Communities and Local Government and Canterbury, 2009) indicating that touring caravans could be ancillary to static ones. MS.

Except for excluding flats or buildings containing flats, the word "dwellinghouse" is not defined in the General Permitted Development Order 1995. In the case of R on the application of Lee v First Secretary of State and Swale Borough Council, 2003, it was held that a building incorporating two caravans was a dwellinghouse for purposes of the four year rule. I am not aware of any court cases or appeals where this issue has been considered in relation to permitted development rights. My reaction, however, is that an ordinary static caravan would not enjoy permitted development rights. If, however, sufficient physical additions have been added for it to become a permanent fixture, it would become a dwellinghouse, though permitted development rights would only apply if it had a defined curtilage.  The point where additions to a caravan change it from a use of land to operational development is considered in section 4.3531 of Development Control Practice. JH. 

I am carrying out an enforcement investigation into a property which is being used as a four-bedroomed house in multiple occupation and is considered to fall within the C4 use class. The property has been extended to provide an additional bedroom. Do dwellings falling within the C4 use class benefit from permitted development under class A, part 1 of the General Permitted Development Order 1995 (as amended)? RH.

In the case of Gravesham Borough Council v Secretary of State for the Environment & Michael O'Brien [1983] it was held that in assessing whether a property was a dwellinghouse one had to examine whether it had the facilities which might ordinarily be expected in a dwellinghouse. Within that context I would not consider a house in multiple occupation to be a dwellinghouse for General Permitted Development purposes and in my experience that view was certainly taken before the recent introduction of the C4 use class.

It might seem anomalous that a property can switch between C3 and C4 uses without needing planning permission and gain or lose permitted development rights in the process. This, however, is analogous to the permitted development rights introduced for schools, colleges and universities and hospitals under the General Permitted Development (Amendment) (England) Order 2010, but not other D1 of C2 buildings  respectively where "switching" could have a similar effect.

From your question it would appear the house has been extended to facilitate multiple occupation use. As this work was not in connection with dwellinghouse use, I consider this work would not be permitted development, though would of course only be expedient to take enforcement action if clear harm form the development could be demonstrated. JH.

Under the General Permitted Development Order 1995 (as amended), a 3m deep extension infilling the "L" of a typical L-shaped terraced house would require planning permission within a conservation area as it is considered to be a side extension. A similar proposal outside a conservation area would be permitted development. As the government has decided that a 3m rear extension is acceptable in impact terms outside of a conservation area, it could be considered unreasonable to refuse a 3m extension within a conservation area solely on impact on the neighbour. To refuse permission would introduce a two-tier approach as impact would be given greater protection inside a conservation area. Your comments are requested, particularly as the proposal raising the issue is contrary to my authority’s adopted 45 degree code. MH.

An analogous situation is where a house in a terrace has been converted to flats. That house would not have permitted development rights for the likes of dormers and outbuildings and in my experience in such instances councils would refuse applications for such works which would have a detrimental impact. Whilst I appreciate your logic that refusing a 3m-deep extension in a conservation area results in a two-tier approach, there is, of course, a counter logic; if a proposal causes harm and the council has powers to prevent that harm, it would be reasonable to expect the council to use its powers. JH.

Can you confirm that in some circumstances there is no restriction under permitted development rights to extensions to the front elevation of a house, other than height, and retaining 50% of the original curtilage unbuilt? This can occur in rural locations where a house’s principle elevation often does not front directly onto a highway. The October 2008 General Permitted Development Order Amendment deals in detail with side and rear extensions, but appears to have no additional restrictions for a principal elevation that does not front a road. PE.

The Permitted development for householders - Technical Guidance note does not really address this issue. The Frequently Asked Questions document which was put on the Planning Portal shortly after the amendment was introduced did discuss this issue and, like you, indicates that the only restrictions in such circumstances are height and the "50% rule". Whilst this advice has been superseded by the Technical Guidance, in this instance it must still be correct. Whilst there will be comparatively few dwellings where advantage can be taken of this provision, those where it can be used will generally be in rural areas as you say. In some instances it might be possible to change a "cottage" to a "mansion" undermining green belt or rural policies aimed at keeping the countryside open. I do consider this to be a provision that should be reviewed. JH.

If allotments are defined as being agriculture under the Town and Country Planning Act 1990 and therefore are excluded from the definition of development, is planning permission required to use any land, no matter what its current use is, as allotments? Can it be argued that a small shed or greenhouse which does not have foundations and is not connected to services, i.e. it is simply placed on paving slabs, is not a permanent building and therefore falls outside the definition of development? PB

s55 of the Town and Country Planning Act 1990 say that the use of land for the purposes of agriculture (or forestry) does not constitute development, so planning permission would not be required to use any land for allotments where their use if of an agricultural nature. If the allotments use is non-agricultural, such as a leisure plot type use, then normally planning permission would be required for their establishment.

Moving on to your second query, deciding whether structures which are moveable or are not attached to the ground require planning permission is quite difficult and section 4.311 of Development Control Practice explains the principles in some detail. The lead case on this issue is Cardiff Rating Authority v Guest Keen Baldwins Iron and Steel Co 1949. The three main issues to be considered are whether the structure’s size was such that normally it would have to be built on site rather than brought to the site ready made; whether the construction suggested some degree of permanence meaning it could only be removed by pulling it down or taking it to pieces and whether the construction was physically attached to the ground. Just because a structure is not attached to the ground does not necessarily mean that it does not require planning permission – for example it has been held placing a shipping container on land requires planning permission where the intention is to keep it there on a permanent basis. Someone who erects a shed or greenhouse on an allotment would normally expect it to remain there many years, so even if it was not attached to the ground, building it would require permission. On the other hand a structure which was intended to be temporary such as a small polytunnel which would remain in place for just one growing season and then be removed would probably not require permission even if it were fixed to the ground. JH.

A blockwork chimney, a domestic biomass (zero carbon) heating installation, was granted permission, subject to a condition requiring a render finish.  The chimney was constructed without being rendered, although it has been painted to contrast with adjacent brickwork. Due to the October 2008 General Permitted Development Order revisions, the chimney would now be permitted development. Paragraph 46 of the 2007 supplement to PPS1 advises authorities in considering whether to take enforcement action to have particular regard to the highest priority placed by Government on mitigating climate change and successfully adapting to the unavoidable consequences. Given this and the change in legislation, would it be expedient and proportional to commence enforcement action for breach of condition? MH

Whilst the chimney was erected for sustainability reasons, whether or not enforcement action is taken does not really affect sustainability issues, so the reference to the supplement to PPS1 is not very relevant. Assuming the chimney was built before October 2008 it would be in breach of planning control, so enforcement action can be taken. Your client would, however, have the theoretical right to demolish the chimney and rebuild it. Fallback rights under the General Permitted Development Order are considered in section 4.346 of Development Control Practice. Generally fallback rights are more relevant to a case the more likely they are to be used. In this instance I consider your client would be unlikely to demolish and rebuild the chimney – rendering would be cheaper. Having said that, my feeling is it would only now be appropriate to take enforcement action if there was a particular reason, such as the chimney looking very unsightly or being in a conservation area. John Harrison.  

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