Some 244,000 of the cheapest rented homes will be lost between 2012 and 2020, the Chartered Institute of Housing has predicted.
It said measures to support construction of rented homes was “desperately needed”, after making projections from government figures that showed the number of homes available at social rents had fallen by more than 120,000 between 2012 and 2016.
Though 44,600 new homes were built for social rent over that period many more were lost through conversions to higher affordable rents or right-to-buy sales, the CIH said.
The institute said the continuing decline in provision was projected on the basis that the government had dedicated the bulk of funding to affordable rents or shared ownership, and that conversions of properties to higher rents and right-to-buy sales would both continue on current trends.
Affordable rents are those let at 80% of market levels under a mechanism introduced by the coalition government. Social rents are lower than this.
CIH chief executive Terrie Alafat said: “The loss of so many of these types of homes is extremely worrying at a time when we need more not less.
“What we’ve seen over the past four years is a very significant decline in the number of homes at social rent; the only type of accommodation which is accessible to a significant proportion of the population.
“If the government really wants to solve our housing crisis it must recognise that building more homes at genuinely affordable rents will be crucial to help those who need housing the most.”
Housing and planning minister Gavin Barwell said in December that he had “no problems” with councils building homes for social rent. He also said he wanted to make sure councils can replace the homes they sell through the right-to-buy.
Communities secretary Sajid Javid told MPs on Monday they “will not have to wait long” for the housing white paper – anticipated to include a number of measures to boost house-building – to be published.