Inspector Anthony Thickett has written to East Devon District Council to say that he does "not consider that the local plan is sound nor at this stage can it be made so by main modification" and has recommended it carry out extra work to address his concerns.
Thickett attacked the plan’s 15,000 home target as not justified by "up to date and appropriate evidence", highlighting the lack of a recent strategic housing market assessment (SHMA) to back up the housing figures.
He said: "The absence of an up to date SHMA is a serious failing and makes a full assessment of need difficult. To rectify this, the council should produce an up to date SHMA to assess the need for housing and affordable housing."
The plan’s housing target is based, said Thickett, on a "low migration scenario figure for East Devon" of 10,800 homes, "plus about 4,000 for overspill from elsewhere (largely Exeter) which has no empirical evidential basis".
The National Planning Practice Guidance (NPPG) advises that the starting point for estimating need should be the latest population and housing projections, which were published in 2011, he points out.
Among Thickett’s other concerns were:
He was not satisfied that the council had demonstrated a five-year housing land supply.
The plan would only have a life of 12 years if adopted in 2014, though the National Planning Policy Framework advises that plans should preferably have a life of 15 years.
An assessment of the accommodation needs of gypsies and travellers would not be completed until this summer and therefore would not be able to inform the local plan.
Thickett wrote: "The production of a new SHMA may take some time and I would appreciate an indication of how long you consider you will need to produce this information in order that we can plan ahead with regard to the length of any suspension and any further hearings that may be required."
In a statement, East Devon Council said the plan's examination "has been paused" while it "undertakes the extra work required by the Inspector to provide clarification on housing numbers and other issues".
It said its planning policy team would produce an action plan "showing the extra work it intends to do and the timing of each stage that will take these tasks through to completion".
In August 2013, according to the statement, the authority agreed to work with Devon County Council, Exeter City Council, Mid Devon District Council and Teignbridge District Council on a new SHMA.
Paul Diviani, the council’s leader, said: "This is pretty much what we expected. It is quite common for an inspector to ask for more information before finding a local plan to be sound.
"This is such a complex subject that it is difficult to get all the boxes ticked in one go.
"After spending so long refining our plans and consulting on them, at some point you have to jump in and say: ‘OK – let’s see how close we are to what the government wants to see’."
Diviani said the council’s original plan was based on the old regional spatial strategy, which the Coalition government has scrapped, but now has to conform to the NPPF and the NPPG, describing the situation as "a moving target".
The authority hopes to go back to the inspector in the autumn with the extra information he needs, the councillor added.
The inspector's letter can be read here.
NOTE: this story was corrected at 11am on Tuesday 8 April to clarify that the inspector's concerns about the evidence supporting the plan's housing target related to its use of low migration figures rather than the government's 2008 population and household projections themselves.