The choice between stay-put and simultaneous evacuation strategy in high-rise buildings has life-or-death implications. Understanding the fire engineering is essential.. The Evacuation Strategy Decision The Grenfell Tower fire exposed the critical importance of evacuation strategy in high rise residential buildings. The choice between stay put and simultaneous evacuation is the most consequential fire safety decision for any residential building over 18m. Stay Put Strategy Principle: Only the flat where the fire originates evacuates. All other residents remain in their flats. Requirements for stay put to work: Robust compartmentation between flats (60 minute minimum) Self closing FD30S fire doors to every flat Ventilated common corridors/lobbies Operational fire detection in common parts Functioning dry/wet riser for fire service use Building designed and maintained to contain fire to flat of origin Advantages: Avoids mass evacuation of hundreds of residents Reduces stairway congestion Residents in safer location (their own flat with closed fire door) Fire service has clear access via stairs Simultaneous Evacuation Principle: All residents evacuate simultaneously on activation of the common fire alarm. Required when: Compartmentation is compromised or unknown Building has combustible cladding not yet remediated Waking watch or common alarm system installed as interim measure Fire risk assessment identifies that stay put cannot be supported Challenges: Evacuation of a 20 storey building takes 30 60 minutes via stairs Stairway congestion can be dangerous (particularly for elderly/disabled) Counter flow with fire service ascending Risk of injury during rushed evacuation The Decision Framework Factor Stay Put Simultaneous Compartmentation Intact and maintained Compromised or unknown Cladding Compliant Non compliant Fire doors Operational with self closers Missing or defective Detection In common parts Full building alarm Population Mobile Significant mobility impairment Fire service Good access and water supply Limited access The Emerging Middle Ground Phased evacuation is emerging as an alternative: Evacuate fire floor + 2 floors above Progressive extension if fire is not controlled Requires sophisticated alarm zoning Increasingly specified for new build HRBs For evacuation strategy advice, contact us. Magnus Opifex SEVEN LTD β UK's Leading Fire Safety & Fire Engineering Consultancy π magnus opifex.co.uk π +44 7486 691724 βοΈ office@magnus opifex.co.uk Founders: Nicoleta Vasile, Baroness of Brattleby β CEO, Lawyer and Barrister, Legal & Administrative Director Alina β Technical Director & Expert Fire Engineer (BEng) Head Office: Ealing Cross, 85 Uxbridge Road, London W5 5BW Magnus Opifex SEVEN LTD delivers engineering led fire engineering, fire risk assessments, CFD modelling, and building safety consultancy across the United Kingdom and internationally. With over 20 years of combined experience and a UK portfolio spanning healthcare, residential and infrastructure, we bring truly engineered solutions with a personal touch. Β© 2026 Magnus Opifex SEVEN LTD. All rights reserved.