The conversion of offices into flats in urban centres poses a “potentially deadly risk” to occupants as the intensity of heatwaves rises, experts have warned.
Further relaxation of planning rules from Sunday mean even more commercial premises can be converted into homes without planning permission. But a failure to provide vital cooling features would make some uninhabitable as the climate crisis worsens, the experts said.
More than 64,000 flats have been built in former offices in the past five years and the rise of home-working during the pandemic is expected to lead to a surge in conversions. The latest government data show a 28% rise in applications since last year.
Permitted development rights (PDR) allow the use of a building to change without planning permission and already applied to offices, but from Sunday they are expanded to cover commercial premises, such as vacant shops, restaurants and gyms. A report commissioned by the government concluded in July 2020 that PDR conversions “create worse quality residential environments in relation to a number of factors widely linked to the health, wellbeing and quality of life of future occupiers”.
The Climate Change Committee, the government’s official advisers, estimates that one in five UK homes already overheat. In 2020, summer heatwaves in England caused 2,556 deaths, and the CCC projects such deaths to triple by 2040 if no action is taken.
Ministers rejected CCC advice in 2015 to bring in new heat-proofing regulations. The CCC repeated its warning in 2019 and said the UK’s lack of plans to protect people from climate crisis was “shocking”. In July, it said it was “absolutely illogical” not to tackle the risks of heatwaves.
“While we recognise the need for more affordable housing, we have concerns about the standard of some homes built under PDR,” said Paul Redington at insurer Zurich UK. “In particular, overheating is emerging as a potentially deadly risk.”
The Royal Institution of Chartered Surveyors and the Chartered Institute of Building share the concerns. Eddie Tuttle at the CIOB said: “There is clear evidence that homes built using PDR has led to spaces detrimental to the health, wellbeing and quality of life of future occupants. Ministers must address these concerns as a matter of urgency.”
He added that PDR conversions had few checks on some aspects of quality, including ventilation and energy efficiency: “Deregulation is part of the problem – what you have to do is regulate sensibly.”
The danger of deadly heat is greatest in small flats and particularly those with only south-facing windows that suffer the full glare of the sun. In some flats, residents may be reluctant to open the windows due to security risks or air pollution.
“Many of these buildings are in city and town centres, which by definition already suffer from the urban heat island effect,” said Redington. Developers could be required to improve cooling by installing shutters on windows, using reflective surfaces and ceiling fans, he said.
“These shocking [PDR conversion] figures are a further damning indicator of the government’s failure to take the threat of heatwaves seriously,” said Bob Ward, of the Grantham Research Institute on Climate Change at the London School of Economics. “Badly designed homes that overheat can be lethal to the occupants in hot weather, particularly if they have underlying health conditions. The government must urgently create and implement a national heat risk strategy.”
A spokesman at the Ministry of Housing, Communities and Local Government said: “Our reforms will transform unused buildings into much-needed new homes, and all new homes must be of high quality and meet national space standards and building regulations – including ventilation requirements.” He said any claim that PDR homes were necessarily of worse quality was unfounded.
A quarter of donations to the Tory party since Boris Johnson became prime minister in July 2019 has come from donors with property interests, the Financial Times revealed last week.
Reddington also said water leaks were disproportionately frequent in converted flats, due to inadequate plumbing for residential use. One London office block converted into 400 flats saw a leak in one ninth-floor home cause £1.5m of damage and forced 36 families in other flats to move out for many months. He said measures to avoid leaks, overheating and fires should be installed during conversion, to avoid expensive retrofits later.