Second staircase requirements confirmed for high-rise residential buildings in England

The Government has confirmed its requirements for a second staircase in new residential buildings in England that are over 18 metres high. This provides clarity for developers, as recent uncertainty over anticipated changes has been holding up development. The changes come into effect from 30 September 2026, however transitional arrangements are in place so that high-rise residential buildings that already have planning permission with a single staircase can continue without further delay.

Transitional arrangements mean that projects that receive building regulations approval before 30 September 2026 and are “sufficiently progressed” by 30 March 2028 can proceed without a second staircase. “Sufficiently progressed” has the same meaning as set out in the recent transitional arrangements for the building control regime for a higher-risk building (HRB) (contained in Schedule 3 of The Building (Higher-Risk Buildings Procedures)(England) Regulations 2023). Namely this constitutes:

• where the building work consists of the construction of a building, when the pouring of concrete for the permanent placement of the trench, pad or raft foundations has started, or the permanent placement of piling has started; or
• where the building work consists of work to an existing building, when that work has started; or
• where the building work consists of a material change of use of a building, when work to effect that change of use has stated.

The requirements are set out in March 2024 amendments to Approved Document B (Fire Safety) Volumes 1 and 2, which accompanies the Building Regulations 2010. This provides more detail on the rules concerning second staircases. For example:

• interlocked stairs (where there is an interlocking staircase providing two separate means of egress within one protected shaft) will be considered as a single escape route and do not constitute an alternative means of escape
• the staircase needs to be at least 1100mm wide
• a protected lobby should not provide direct access to more than one stair
• an escape route should not pass through one stair enclosure to reach an alternative exit

The guidance does not use the “higher-risk building” definition, set out within the Building Safety Act 2022 (BSA). Instead, it specifies that “flats should be served by more than one common stair if…

1. the flat is on a storey that does not meet the criteria for a single escape route or a small single stair building [or]
   
2. the building has a top storey of 18m or more in height.”

The reference to “flats” is akin to the requirement under the BSA that a HRB has at least two residential units and as an HRB would also be at least 18 metres high, it is likely that the guidance on second staircases will be used alongside the HRB regulation.

Compliance on these matters will be checked as part of the fire safety review process for HRBs undertaken by the Building Safety Regulator. This will occur at Gateway 1 (where the planning stage is reviewed by a fire safety professional) and Gateway 2 (where building regulations approval is reviewed by a multi-disciplinary team).

The Government initially consulted on a 30 metre height threshold, but has extended this to buildings over 18 metres following feedback. This will be welcomed by fire safety campaigners, as staircases are an essential means of escape for residents and an important means of access for emergency services. There are no current plans to legislate for the retrofit of existing HRBs with a second staircase. The Government is keen to state that existing HRBs with a single staircase are not inherently unsafe, provided they have been built in accordance with relevant standards, are well maintained and properly managed. The Government expects lenders, managing agents and insurers not to add any additional hurdles or onerous criteria on single-staircase buildings. There is hope that any fears will be ameliorated by the awaited regulations in response to a recent consultation on personal emergency evacuation plans for existing HRBs.