More than 423,000 homes across England and Wales are still waiting to be built after being given planning permission, according to new research published by the Local Government Association (LGA).
The study, commissioned by the LGA and carried out by industry body Glenigan, said the backlog had grown by almost 16% in the last year.
In 2015/16, the total number of unimplemented planning permissions in England and Wales was estimated at 365,146, rising to 423,544 in 2016/17.
The LGA said the findings suggest developers are taking longer to build new homes.
It now takes 40 months, on average, from schemes receiving planning permission to building work being completed – eight months longer than in 2013/14, the LGA said.
The LGA, which represents 370 councils in England and Wales, said councils are approving nine in every 10 planning applications.
It said councils need powers to act on uncompleted schemes, including making it easier to compulsory purchase land where homes remain unbuilt, and to be able to charge developers full council tax for every unbuilt development from the point that the original planning permission expires.
Cllr Martin Tett, LGA housing spokesman, said: “To tackle the new homes backlog and to get the country building again, councils also need the freedom to borrow and invest in desperately needed new homes.”
He continued: “Our national housing shortage is one of the most pressing issues we face.
“While private developers have a key role to play in solving our housing crisis, they cannot meet the 300,000 house building target set by the Government on their own.
“We have no chance of housing supply meeting demand unless councils can get building again.”
But the Home Builders Federation claimed the study is “overly simplistic”.
Andrew Whitaker, planning director at the Home Builders Federation, said: “Housing delivery is up 74% in four years and the fact more applications are being submitted demonstrates builders’ commitment to build more.”
He continued: “The majority of permissions in this overly simplistic study are on sites where construction is already under way, or where a full permission that allows builders to actually start work has not yet been granted.”
A Ministry of Housing, Communities and Local Government spokesman said: “We are determined to build the homes our country needs, and new homes should be built as soon as possible once permission has been given.
“Ministers have been clear government needs to play a more active, more muscular role ensuring homes get built now.
“We have also asked Sir Oliver Letwin to review how long it is taking to build new homes and his preliminary report will be ready in time for the Spring Statement next month.”
Here is a regional breakdown of the research from the LGA, with the estimated number of uncompleted builds in 2016/17:
East Midlands, 29,933
East of England, 44,946
London, 101,449
North East, 17,342
North West, 61,468
South East, 61,237
South West, 34,929
West Midlands, 32,879
Yorkshire and the Humber, 28,597
Wales, 10,764