Local authorities would also have to buy expensive land to build on, adding to the cost.
Figures from Savills show there are more than 27,000 acres of council-owned land in England to build homes on.
But Emily Williams, a research director at the company, says the vast majority of those sites would be costly to redevelop.
“Council housing delivery isn’t as simple as just increasing grant funding,” she adds. “It is important that expanding affordable housing development doesn’t crowd out private sector, open market-focused delivery.
“An increase in affordable housing funding would need to be accompanied by an increase in development land supply, which is starting to happen through Labour’s recent planning reforms, but remains a long way below target.”
Steve Turner, the executive director of the Home Builders Federation, also warns that the costs would be immense if Burnham returns to the municipal housebuilding model of old.
“Going back to the 1970s council houses model would require massive public investment and I don’t think that is currently realistic,” he says.
“You can’t suddenly develop an in-house council housebuilding capacity overnight. It takes time. The quickest delivery model for housing, of whatever tenure being specified, is currently through the private sector.
“The better way … is by stimulating private sales, which then will bring more affordable homes.”
