A safety regulation introduced in the wake of the Grenfell Tower disaster is being blamed for the loss of tens of thousands of new homes, as developers warn that a requirement for second staircases in mid-rise blocks is making large swathes of housing unviable.
The rule, announced in 2023 by then housing secretary Michael Gove, requires all residential buildings taller than 18 metres to include a second staircase. Although enforcement does not formally begin until September 2026, lenders, insurers and investors have already begun insisting that new schemes comply.
For Paul Rickard, founder of affordable housing developer Pocket Living, the change proved fatal to a planned 50-home development in Hackney, east London.
“We simply didn’t have room for a second staircase,” Rickard said. “We would have lost a home on every floor, and once you take those out, the numbers don’t work. We’d already spent £1 million on the site and planning. In the end, we had to abandon the project entirely.”
Pocket Living later sold the site, which is now being considered for use as a morgue.
The second staircase requirement is one of a series of sweeping reforms introduced after the 2017 Grenfell fire, in which 72 people died. Before the change, England was unusual in allowing high-rise residential buildings of any height to be built with a single staircase.
Supporters of the rule argue that additional staircases improve evacuation times and prevent congestion between firefighters and residents during emergencies.
“You cannot fight a fire and evacuate a building simultaneously in a single shaft,” said Adrian Dobson, executive director at the Royal Institute of British Architects. “Even if the staircase is not compromised by smoke, it’s compromised by firefighting.”
However, critics argue that while second staircases may improve safety in very tall buildings, the government’s chosen threshold of 18 metres, roughly six storeys, is excessive.
According to analysis by Place Base, an advisory firm working with developers, the safety benefits of second staircases in buildings below 50 metres are negligible.
Using the government’s own impact assessment, Place Base found that in buildings between 18 and 30 metres, a second staircase would save just 0.004 lives during a “major incident”, events that officials estimate have a one-in-50,000 chance of occurring.
Over a 70-year period, the modelling assumes fewer than three such incidents nationwide in buildings of that height, equivalent to one death every 6,153 years.
“It was a shock that the threshold was set at 18 metres,” said Jamie Ratcliff, co-founder of Place Base. “There simply isn’t a safety case for it. The figure was chosen because it aligns with the government’s definition of a ‘higher-risk building’, not because it saves lives.”
While the safety gains are disputed, the impact on housing supply is already being felt. Place Base estimates that around 18,000 homes a year are no longer being built as a direct result of the rule, either because schemes have been scrapped or because developers are scaling buildings down to avoid crossing the 18-metre threshold.
Rickard described another London scheme where he cut the height from seven storeys to six to avoid the extra staircase. “That decision alone meant 14 fewer affordable homes,” he said.
Over five years, Place Base estimates that around 90,000 homes, equivalent to a city the size of Milton Keynes, could be lost.
Anthony Breach, director of policy and research at the Centre for Cities, said the rule was having “purely destructive” consequences.
“If there were a clear trade-off between safety and cost, people would accept higher costs,” he said. “But there’s no evidence that the 18-metre threshold improves safety. Meanwhile, we’ve made the only form of housing that can meet demand, dense, mid-rise urban housing, extraordinarily expensive.”
Both Place Base and Centre for Cities are urging ministers to raise the threshold to 50 metres, where official modelling shows a meaningful increase in lives saved. Such a move would still capture buildings like Grenfell Tower, which stood 67 metres tall, while easing pressure on housing delivery.
A 50-metre threshold would also bring England broadly into line with countries such as France, Sweden, Denmark and China, and remain more cautious than Germany, Switzerland and Italy.
“There are many reforms that genuinely matter for safety, sprinklers, removing flammable cladding, better building management,” Ratcliff said. “But some measures have been introduced under the banner of safety that aren’t saving lives at all. This is one of them. If anything, it may be costing lives by worsening overcrowding and homelessness.”
A spokesperson for the Ministry of Housing, Communities and Local Government rejected the analysis, saying Place Base’s estimates did “not align” with government forecasts.
“There is wide consensus among experts that second staircases improve safety by providing additional escape routes,” the spokesperson said, adding that the government remained committed to delivering 1.5 million new homes “without compromising on safety”.
For developers and housing analysts, however, the concern remains that a well-intentioned rule is quietly undermining one of the government’s core policy ambitions — building enough homes to meet demand, with little evidence that lives are being saved in return.
