Horsham district is being asked to find more sites for housing because neighbour Crawley cannot meet its requirements.
Planners should find sites for an increased figure of 800 a year up to 2031, a top planning inspector has decided, because Crawley cannot find enough space.
That would mean by 2031 Horsham District would have 16,000 more homes, enough for well over 32,000 people.
Horsham District Council said this week it was disappointed but would be considering the requirement in detail and responding to it.
Cllr Claire Vickers, cabinet member for planning and development, said: “We have received a note from the Inspector requiring us to make two final modifications to the Horsham District Planning Framework in order that he can approve it.
“In light of Crawley’s projected housing shortfall, the Inspector is requiring us to increase the number of dwellings to 800 per year for the plan period, 2011-2031 This would result in a total of 16,000 dwellings between 2011 and 2031. We do not need to find or consult on these additional numbers now, but must start to review the plan within three years of adopting it, with a view to identifying extra numbers that may be required.
“Whilst I am disappointed that the numbers have been increased to 800, this note from the Inspector does give us some certainty for the foreseeable future.
“The second modification is to reflect a change in government policy as regards wind farms.
“The council is considering the Inspector’s Note in detail and will respond to him very shortly.”