Quick answer: On 16 September 2026 MHCLG republished both volumes of Approved Document B. They are now titled the 2019 edition incorporating 2020, 2022, 2025 and 2026 amendments, collated with 2029 amendments — meaning the 2026 amendments are now inside the main document, not sitting in a separate booklet alongside it. GOV.UK’s own update note describes the change as introducing “guidance on second stairs and evacuation lifts in taller residential buildings”. The amendments come into force on 30 September 2026. If you have a residential scheme at or above 18m, the practical action this week is to confirm which PDF your design team and your building control body are each working from.
What actually changed on 16 September
Nothing in the policy changed. What changed is the document.
Since March 2025, the published version of Approved Document B has been the 2019 edition incorporating the 2020, 2022 and 2025 amendments, collated with the 2026 and 2029 amendments. “Collated with” meant the future changes were shown for information — visible, but not yet part of the operative guidance. The 2026 changes lived in their own amendment booklet, issued with MHCLG Circular 04/2024.
As of 16 September, the titles read differently:
- Volume 1: Dwellings — 2019 edition incorporating 2020, 2022, 2025 and 2026 amendments, collated with 2029 amendments. 200 pages.
- Volume 2: Buildings other than dwellings — same basis. 224 pages.
The 2026 amendments have moved from “collated with” to “incorporating”. The 2029 amendments — the removal of BS 476 references for fire resistance, in force 2 September 2029 — remain collated for information.
We wrote a fortnight ago that if you were working from a version of ADB and were not sure which one, that was the question to resolve this month. This is why. The answer has now changed.
The evacuation lift point
Circular 04/2024’s summary table describes the content of the 2026 amendment booklet in a single line: “Second stair provisions in residential buildings over 18m in height.”
GOV.UK’s update note for 16 September is broader. It says the updates “introduce guidance on second stairs and evacuation lifts in taller residential buildings.”
That is worth reading properly rather than assuming. Disabled evacuation was one of the most heavily argued points in the consultation response — respondents pressed for the draft BS 9991 approach of evacuation lifts operable in managed and automatic mode, with protected evacuation lift lobbies, to be brought into ADB. If your scheme is at or above 18m and your fire strategy was written against the pre-2026 text, the lift and lobby provisions are the part most likely to have moved underneath you.
The detail sits in the reissued volumes. Read the sections rather than the summary.
The dates that matter, unchanged
The 2026 amendments come into force on 30 September 2026. The transitional arrangements in Circular 04/2024 are unchanged by this week’s republication:
The old guidance still applies where a building notice or initial notice was given to, or a building control approval application with full plans was made to, the relevant authority before 30 September 2026, and the work has started and is sufficiently progressed either before that day or within 18 months beginning on that day — so by the end of March 2028.
“Sufficiently progressed” means, for new construction, that the pouring of concrete for the permanent placement of trench, pad or raft foundations has started, or permanent piling has started. For work to an existing building, that the work has started. For a material change of use, that work to effect the change has started.
The base version being amended is the 2019 edition incorporating the 2020, 2022 and 2025 amendments — that is, the document as it stood before Tuesday.
What to do this week
Fix the version in writing. For every live scheme at or above 18m, record which edition of ADB the fire strategy was assessed against, and confirm your building control body is holding the same one. A version mismatch discovered at handover is expensive; discovered now, it is an email.
Re-read the lift provisions, not just the stair provisions. The stair requirement has been trailed since 2024 and most teams have absorbed it. The evacuation lift and lobby guidance has had far less attention.
Confirm submission dates from the building control body. The 18-month transitional route turns on when the notice or application was actually made and recorded — not the date in your programme. Get it confirmed by the body that holds it.
Check the height measurement if you are near the line. 18m is a threshold, and schemes cluster around thresholds. How height is measured under ADB is a question to resolve before you rely on being under it.
Why the document keeps moving
Since April 2023 the Building Safety Regulator has had a duty under the Building Safety Act 2022 to keep the safety and standards of all buildings in England under review, which includes advising government on updates to the Approved Documents. In December 2025 BSR published its continuous review of Approved Document B collection, alongside ten research projects covering everything from balconies and laminated glass to fire spread over pitched roofs with solar panels.
The stated intention is planned changes at regular intervals rather than occasional large rewrites. For anyone maintaining a house type library or a standard fire strategy, that means version control stops being administrative housekeeping and becomes part of the compliance record.
The short version
The policy has not changed. The document has. As of 16 September 2026, Approved Document B volumes 1 and 2 incorporate the 2026 amendments, which take effect on 30 September. Second stairs at 18m are the headline; evacuation lifts are the part worth reading again. If you are relying on the transitional route, the submission date on the building control body’s record is the only date that counts.
If your scheme sits close to a fabric or overheating threshold as well as a height one, ΨMonkey will give you defensible junction-by-junction thermal bridging figures rather than a blanket value — useful when a late change to cores and lobbies pulls the envelope around with it.
Sources: GOV.UK — Fire safety: Approved Document B (updated 16 September 2026) · GOV.UK — Approved Document B (Fire Safety): new updates to support enhanced fire safety, MHCLG Circular 04/2024 · GOV.UK — Consultation response: Amendments to Approved Document B, second staircases · GOV.UK — Continuous review of Approved Document B (Building Safety Regulator)