Major Updates to Approved Document B: What Architects Need to Know in 2025 and Beyond

The world of fire safety regulations is constantly evolving, and as of March 2025, significant changes to Approved Document B (ADB) are now in force. Whether you’re a Part 3 student preparing for your final leap into architectural practice or a seasoned architect seeking a refresher, staying up to date with these changes is crucial for compliance and safety.

Let’s break down the latest amendments, what’s coming next, and how you can prepare your projects for the future.

The 2022–2024 amendments to ADB introduced requirements like second staircases in tall residential buildings, updates to evacuation shafts, and new fire doorset provisions. These were part of a broader effort by the Department for Levelling Up, Homes, and Communities to enhance fire safety standards following the Grenfell Tower tragedy.

The Latest Amendments: March 2025 and Beyond

As of March 2025, a new cycle of updates to Approved Document B has begun, marking the culmination of consultations and phased changes that started in 2022. The government released three amendment booklets in September 2024, each with its own timeline and focus:

Booklet	In Force	Key Updates
1st	March 2, 2025	Regulation 38 updates, removal of BS 476 for reaction to fire/roofs, new sprinkler rules for care homes
2nd	September 30, 2026	Second staircases in 18m+ buildings, evacuation lifts guidance
3rd	September 2, 2029	Removal of BS 476 for fire resistance, full transition to European standards

All three updates are consolidated in the latest version of Approved Document B: Fire Safety - Volume 1: Dwellings (2019 edition, with amendments through 2029).

What’s Changed as of March 2025?

1. Sprinklers in Care Homes

• All new care homes—regardless of height—must now be fitted with sprinklers.

• Compartment sizes are limited to 10 beds, and self-closing devices are required on doors.

• Previous allowances for increased bed numbers or omitting self-closing devices when sprinklers were installed have been removed.

2. Regulation 38 Updates

• Duty holders must provide comprehensive fire safety information to the responsible person, who must formally acknowledge receipt and adequacy.

• Third-party certification is now required to ensure accurate communication of fire safety information, creating a clear documentation trail.

3. Reaction to Fire: Out with BS 476, In with BS EN

• The national classification system (BS 476) for reaction to fire and roofs has been removed.

• The European Standard (BS EN 13501 series) is now the only accepted route for classification.

Looking Ahead: 2026 and 2029

September 2026: Second Staircases and Evacuation Lifts

• Second staircases become mandatory in new residential buildings over 18m.

• At least one lift must be an evacuation lift in such buildings.

• Projects approved before this date must have started and progressed sufficiently within 18 months, or risk lapsing and needing to reapply under new rules—potentially triggering costly redesigns.

BS 9991:2024—New Guidance for Residential Buildings

• The updated BS 9991 standard, effective since November 2024, aligns with these changes and is now the recommended route for planning applications as of March 2025.

• Key updates include stricter height limits for single-stair buildings, expanded guidance on evacuation lifts, and new recommendations for care homes and timber structures.

September 2029: Full Transition to European Standards

• All references to BS 476 for fire resistance will be removed.

• Only the European Standard (BS EN) will be recognized for fire resistance classifications, ending the dual system and simplifying compliance.

What Architects Need to Do Now

• Plan Ahead: Advise clients early about these changes to avoid project delays and costly redesigns.

• Stay Compliant: Ensure all new care home designs comply with the latest sprinkler and compartmentation requirements.

• Update Specifications: Use Approved Dcoument Bthe BS EN 13501 series for fire reaction and resistance classifications in all new projects.

• Adopt the Latest Standards: For residential buildings, transition to BS 9991:2024 for planning and building control applications.

Final Thoughts

These updates to Approved Document B represent a major shift in fire safety regulation, aiming for greater clarity, accountability, and safety in the built environment. By staying informed and proactive, architects can ensure their projects meet the highest standards—protecting both lives and professional reputations