Last month, the government’s Office for National Statistics (ONS) published the 2016-based household projections, which showed a 24 per cent drop in the scale of anticipated growth compared to the previous 2014-based projections.
The household projection data is a key input into the new standard method of assessing housing need, and the new figures have prompted dramatic drops in many councils’ housing need figures when factored into the standard method.
The standard method was introduced in July's revised National Planning Policy Framework (NPPF), which states that it should only apply to local plans that are submitted for examination after 24 January next year, but applies to decision-making, including appeals, immediately.
The government's updated Planning Practice Guidance states that councils calculating their housing land supply should use their local plan housing target if their plan is less than five years old, but if it is older should use their local need figure calculated by means of the standard method.
According to the NPPF, if a council does not have a five-year housing land supply, it faces the presumption in favour of sustainable development.
Several planning consultants have said this means that councils with an out-of-date local plan, where their local housing need has dropped, have seen their housing land supply increase. And, for some, it has pushed them over the five-year threshold, thus avoiding the presumption penalty.
Jonathan Dixon, associate director at consultancy Savills, said: "The new figures change immediately any calculation of a standard method figure and thus any projections of five-year housing land supply in an area that relies on a standard method figure.
"In places, the housing land supply will have increased significantly overnight, while in other places it will have decreased.
"Where applications and appeals thus stood to be approved, they might well now be refused, and vice versa."
Dixon said this could lead to applicants withdrawing applications and authorities pausing their processing, pending the government’s review of its standard method.
Andrew Lowe, senior planner at consultancy Turley, said: "The numbers have created chaos.
"It’s having an immediate impact on appeals. Strong housing land supply cases have just fallen apart.
"Developers will be concerned by this, especially where they’ve got appeal cases ongoing. A lot will have submitted appeals based on high housing figures, and potentially those appeals are damaged.
"You have to hope an inspector, if a whole case came down to consideration of these figures, would consider a range of figures in the round."
Paul McColgan, associate director at consultancy GL Hearn, said: "There could be a hiatus in submission as this makes it more difficult to argue cases on the basis of a lack of five year land supply.
"When pushing through a case on the presumption in favour, it looks like they’ve suddenly had the rug pulled from under their feet."
Simon Elliott, planning associate at consultancy Bidwells said: "You could see an awful lot of councillors putting pressure on officials to amend their five-year housing land supply documents.
"I hope that most planning authorities sensibly hold fire before making rapid changes."
A workshop session on the new National Planning Policy Framework's standard method for assessing housing need, led by David Roberts, team leader (planning for housing need, Ministry of Housing, Communities and Local Government) will take place at next week's Planning for Housing conference. For full details and to book your place, click here.