Approved Document B Amendment — Second Staircase for Residential Buildings over 18m

Approved Document B Amendment — Second Staircase for Residential Buildings over 18m. Requires all new residential buildings over 18 metres to have at least two staircases. Reduces the single-staircase threshold from 30m. A direct response to evacuation concerns raised by the Grenfell Tower fire. This page provides a structured summary, key provisions, and practical guidance on the application of Second Staircase Requirement (ADB 2024 Amendment) to UK fire safety engineering, building design, and Building Safety Act compliance.