Second staircase guidance takes effect on 30 September 2026

Amended guidance in Approved Document B Volume 1 recommending a second staircase in blocks of flats with a storey 18 m or more in height takes effect on 30 September 2026. MHCLG confirmed the threshold and the date in circular 04/2024.

The transitional provisions are the operative detail

The 2019 edition, incorporating the 2020, 2022 and 2025 amendment sets, continues to apply where a building notice, initial notice or building control approval application was submitted before 30 September 2026 and the work is sufficiently progressed before that date or within eighteen months afterwards — giving a longstop of 30 March 2028.

Both limbs have to be satisfied. A notice submitted in good time on a scheme that then stalls does not preserve the earlier position indefinitely, and that is the detail most likely to catch a project out.

Guidance, not a regulation

Worth stating plainly, because this provision is routinely described as though the Building Regulations had been amended. They have not. The Building Regulations set functional requirements; Approved Document B describes a way of meeting them. The second staircase recommendation is guidance on satisfying an existing requirement, not a new requirement in its own right — which is why a departure remains possible where it can be justified, and why "we are not following ADB" is a position that has to be demonstrated rather than simply asserted.

How it relates to the consultation

This is a separate and already-settled change. The consultation that closed on 1 July 2026 proposed a further and wider set of amendments, including evacuation lifts above 18 m. The second staircase date below is fixed; that consultation's outcome is not yet.

For existing buildings

Nothing here retrospectively changes an occupied building. What it changes is the benchmark for new work, and therefore what a building completed after this date should have been given — which is where the original expectation comes from when an assessment finds a protected route compromised years later.