A detailed breakdown of the latest changes to ADB and their practical implications for designers.. What's Changed in ADB 2025 The Ministry of Housing, Communities and Local Government has published significant amendments to Approved Document B. Key Changes 1. Sprinkler requirements extended to all new residential buildings over 11m (previously 18m) 2. Second staircase requirement for residential buildings over 18m confirmed 3. Evacuation lifts mandatory in all new buildings over 18m 4. Wayfinding signage requirements enhanced for complex buildings 5. Smoke control ventilation rates increased by 15% 6. External wall guidance aligned with BS 8414 test criteria Impact on Projects These changes affect all planning applications submitted after 1 October 2025. Projects already in construction are not affected, but designers should consider voluntary adoption where practical. For ADB compliance guidance, contact us.