Second Staircase Guidance
What Has Changed for Residential Buildings?
Evolution in the UK’s building safety landscape continues, and one of the most significant recent changes affects the design of new residential developments. From the 30th September 2026, updated guidance in Approved Document B introduces new requirements for second staircases in certain residential buildings, with the aim of improving means of escape and greater fire safety.
What is the Second Staircase Requirement?
The updated guidance states that new blocks of flats with a top storey measuring 18 metres or more above ground level should be provided with more than one common staircase. This highlights a significant shift in residential building design and implements recommendations made following extensive building safety reviews and consultations.
The requirement applies to new developments subject to the updated guidance and is intended to provide residents and firefighters with an additional protected route should one staircase become compromised during an emergency.
Why has the guidance changed?
The introduction of a second staircase is part of a wider programme of fire safety reforms following the Grenfell Tower Inquiry and the implementation of the Building Safety Act 2022. The government has stated that additional escape routes can improve building resilience and provide greater protection for occupants in taller residential buildings.
By requiring a second means of escape in buildings above 18 metres, the guidance aligns with broader measures aimed at strengthening safety standards across higher-risk residential developments.
The updated guidance does not introduce a retrospective requirement to add second staircases to existing residential buildings that currently have only one stair. Instead, the focus is on new developments and projects progressing through the building control process.
What Buildings Are Affected?
The guidance applies primarily to new blocks of flats where the top occupied storey is at least 18 metres above ground level. Importantly, the height threshold is inclusive, meaning a building measuring exactly 18 metres falls within the scope of the guidance.
The changes are not a blanket requirement for every residential building and do not automatically apply to hotels, houses or other accommodation types, which are covered by different fire safety provisions.
What About Existing Buildings?
The updated guidance does not introduce a retrospective requirement to add second staircases to existing residential buildings that currently have only one stair. Instead, the focus is on new developments and projects progressing through the building control process.
Transitional arrangements are available for some schemes that had already progressed through the building control process before the new guidance came into force, subject to specific conditions.
Looking Ahead
The second staircase guidance marks another important step in the UK’s ongoing building safety reforms. For developers, architects, contractors and building owners, understanding the new requirements will be essential when planning future residential schemes. Now, early consideration of fire safety, means of escape and building design can help ensure projects remain compliant while delivering safer homes for residents.