Q. Can the upgrading or modification of radar instruments on civil and military airports be addressed through a planning condition on a wind energy developer when permission is given for nearby turbines?

I struggle to grasp how such a condition could pass the tests in Circular 11/95 on conditions when the applicant has no interest in the land in question, the developer has no power to carry out the mitigation detailed in the condition and the mitigation works would need the consent or authorisation of a third party to carry out. Surely the correct approach is to deal with this via a section 106 agreement between the airport operator, the planning authority and the developer? MP

A. The courts have made numerous judgements about the validity of such "negative conditions", which require off-site actions before development can go ahead, following the ruling in Grampian Regional Council v City of Aberdeen (1984). The legal situation seems to be that a condition is not invalid just because it prevents development until something has been done, even if it is outside the applicant's control. In any case, an applicant should not be deprived of permission just because there is no prospect of the development taking place. Government policy - which is not the same as the law - indicates that negative conditions should only be imposed if the steps required are reasonably likely to be implemented before the permission lapses. Applying these principles to this case, a condition preventing development until a third party has upgraded a radar installation to eliminate screen clutter from turbine blades would be legally valid even if the third party has no intention of cooperating. But it would only meet the tests in government circulars if there is clear evidence that the third party is willing to carry out or allow the upgrade and that it would be effective. Graham Self

A British Railways Board v Secretary of State for the Environment and London Borough of Hounslow (1994) indicated that a Grampian-style condition can legally be imposed even if there is no prospect of the required action being carried out. John Harrison


Permission was granted for a class A3 restaurant and cafe use subject to conditions such as restrictions on operating hours. Following its implementation, the building's use was changed to class A1 retail under the provisions of the General Permitted Development Order 1995 as amended. Do the conditions on the A3 permission still apply to the A1 use? SP

Is planning permission or conservation area consent required to remove a church hall chimney in a conservation area? SD

Do you have an answer to these questions? If so, please email it to Forum editor John Harrison at by 21 November. We also welcome your queries, which can be emailed to the same address.

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