Measures proposed to mandate second staircases in residential tower blocks over 30 metres

The Department for Levelling Up, Housing and Communities (DLUHC) is consulting on proposals to introduce measures to mandate second staircases on new residential tower blocks in England over 30 metres to improve fire safety. Existing tower blocks over 30 metres with one staircase would not be affected.

The consultation which is due to close on 17 March 2023 acknowledges that DLUHC needs to "review the evidence base and more fully understand the risks" as the significant change may make some developments "unviable" by increasing costs and reducing saleable floorspace. Initial estimates are that this measure would cost in the region of £1.6 billion over a decade.

The proposed change would be implemented through an amendment to Approved Document B, which provides statutory guidance on how to meet the Building Regulations.

In support of the plans in the consultation and the implementation of a national position, the London Mayor has separately directed that planning applications which involve residential buildings in London over 30 metres in height will need to be designed to provide two staircases. A statement regarding fire safety and tall buildings by the GLA makes it clear that planned buildings over 30 metres tall will “need to be designed to provide two staircases before they are referred to us at Stage 2 for the Mayor’s decision”.

Second Staircase proposals

The consultation states that DLUHC is concerned that "some tall residential buildings are being designed with a single staircase without due consideration by the designers on the level of safety provided and the necessary resilience."

A second staircase could "provide some benefits for very tall residential buildings such as added resilience for extreme events and reduced conflicts between emergency responders entering a building and those trying to escape, reducing the risk of the smoke ingress into an “escape” stairwell".

Any measures introduced seem likely to include distance and fire resisting separation between the two staircases to protect against the spread of smoke making the use of scissor or interlocking staircases unlikely.

What is the proposed height threshold?

DLUHC's proposals are that the height threshold where a second staircase should be provided is 30 metres as this is "an accepted threshold for increased safety measures such as increased fire resistance provisions".  However, the consultation invites responses as to whether alternative height thresholds might be more appropriate, for example 11 m or 18 m. A threshold of 18 metres is recommended by The National Fire Chiefs Council which is also supported by the Chartered Institute of Housing.

The proposed change would affect new residential buildings in England, but not existing tower blocks over 30 m that have only a single staircase.

When would these changes come into effect?

The proposals are being consulted on and DLUHC have indicated a "very short transition period" before implementing the change. The exact period is not set, but would allow time for schemes in development to be completed but would "not allow the opportunity for developments to get off the ground ahead of the new requirements coming into effect". As a result, the consultation encourages all developments to prepare for this change.

In view of the short transition period, the London Mayor's statement of support for a requirement for second staircases in new residential buildings over 30 metres in London comes into immediate effect. The GLA's planning team is now working to progress schemes currently in the pipeline to ensure that they include two staircases where necessary before any Stage 2 referral.

Anything else?

The consultation also includes plans to make sprinklers mandatory in all new care homes, regardless of height, and to remove references to national British Standards from Approved Document B. In place of those national standards the plans would be to refer to British versions of European standards.