The idea for Place Base’s first published research emerged from a nagging desire to quantify how many new homes were being lost to the previous Government’s decision to impose second staircase requirements at a much lower height that had been anticipated. Last year in every conversation I had in relation to development I learned new examples of planned buildings that were being reduced in height to avoid the requirement.
Our research, published in the report ‘Milton Keynes Lost’, reveals that the July 2023 decision to mandate second staircases in all residential buildings over 18 metres will result in approximately 90,000 fewer homes being built over the next five years. That is roughly the size of Milton Keynes, one of Britain’s most successful new towns.
Of course there are people who say that this is a price worth paying to make safer buildings but this ignores just how weak the safety case for second staircases is. The human impacts from not building enough homes will undoubtedly be much higher. Building fewer homes means that tens of thousands of households will be living in less suitable, safe accommodation. It means that any reduction in the 172,000 children currently living in Temporary Accommodation will be slower and there will be tragic consequences. In a single year 80 children died living in Temporary Accommodation and over a five year period 74 children died with Temporary Accommodation as a contributing factor to their vulnerability, ill-health or death. This contrasts with the government’s analysis that the second staircase requirement would prevent one death in major fires in buildings 18 to 30 metres in height every 6,153 years.
In such fires – assumed to have a one in 50,000 chance of occurring – government analysis is that the second staircase requirement would save 0.004 lives per incident. The Times covered our findings, including a real example from a stalled Pocket Homes development that is now being progressed as a morgue and support from Centre for Cities who have been calling for the second staircase height requirement to be lifted to 30 or 50 metres. The Times article also points out that in the event of a fire people escaping from a building would be likely to use both staircases and that Grenfell Tower was 67 metres in height. Grenfell Tower also did not have the compartmentation, smoke extraction and fire suppression measures that a modern building is required to have.
I’m clear that there are a huge number of things that have been really important in addressing life safety concerns post-Grenfell, most notably increased requirements for sprinklers – which have very clear benefits – but also removing flammable cladding, increased compliance requirements on how buildings are operated and increased consumer regulation in social housing. The second staircase requirement is not in the same league.
Government admits this, estimating a benefit-cost ratio of just 0.007. Put simply, for every £1,000 spent implementing this measure, society receives £7 in safety benefits.
In producing the research the point that shocked me the most was that the Government’s impact assessment had not even considered the possibility that developers would reduce the height of planned buildings to avoid the requirement. In the real world I’ve only spoken to one who hasn’t.
The Government’s own data shows that material safety benefits are concentrated in buildings over 50 metres. Yet the threshold was set at 18 metres primarily for administrative alignment with buildings overseen by the Building Safety Regulator – a definition that is itself under ongoing review. This matters enormously. Buildings between 18 and 30 metres represent a crucial segment of urban housing supply. They are tall enough to achieve density in our cities, but not so tall as to require the complex engineering and higher costs of genuine high-rise construction. By imposing second staircase requirements at 18 metres, the government has created what our research identifies as a “viability chasm” for precisely the types of mid-rise buildings that make urban living work.
When we looked at how other countries approach this issue, a clear pattern emerged. France requires second staircases only above 50 metres. Finland sets the threshold at 52 metres. Germany, Ireland and Singapore all use 60 metres. These are not countries with poor safety records or lax building standards. They are jurisdictions that have balanced safety requirements with housing delivery.
Intriguingly, the international trend is moving in the opposite direction to the UK. Twenty US states and eleven US cities have recently moved to allow single staircases in mid-rise buildings. Canadian jurisdictions are following suit. These changes are happening because the evidence shows that properly designed single-staircase buildings with modern fire safety systems perform well in practice.
Our research makes a clear recommendation: raise the threshold for mandatory second staircases to 50 metres. This would align with the government’s own data showing where material safety benefits are concentrated. It would bring the UK into line with European comparators like France and Finland. Most importantly, it would immediately restore viability to thousands of urgently needed urban homes.
This is not about compromising safety. Modern fire safety is about systems, not single measures. Sprinklers, fire-resistant materials, alarm systems, evacuation procedures and building management all contribute to safety outcomes. A properly designed and managed building with a single staircase and comprehensive fire safety measures will be much safer than a poorly managed building with two staircases.
We hope our research prompts a serious reconsideration of this policy. Britain needs more homes. We need them to be safe. But we also need our safety requirements to be proportionate, evidence based and aligned with international best practice. The current second staircase rule meets none of these tests. We welcome engagement from policymakers, industry and safety experts on these findings.
Jamie Ratcliff is Co-founder of Place Base, a strategic advisory firm supporting organisations working in and around housing
