Choosing the wrong evacuation strategy can cost lives. We compare stay-put, simultaneous, and phased evacuation approaches, explaining when each is appropriate and how recent regulatory changes affect the decision.. Why Evacuation Strategy Matters The evacuation strategy is arguably the single most important decision in a building's fire safety design. It determines how every other fire safety system is specified — from the number and width of staircases to the fire resistance of compartmentation and the type of alarm system installed. Get it wrong, and you create a dangerous mismatch between the building's physical capabilities and what occupants are expected to do in a fire. The Three Primary Strategies Stay Put Principle: Only the dwelling where the fire originates is evacuated. All other residents remain in their flats. Relies on: Robust compartmentation (minimum 60 minutes) Effective fire doors throughout Adequate firefighting facilities Single protected staircase designed for firefighting access Appropriate for: Purpose built blocks of flats with adequate compartmentation Buildings where compartmentation has been verified and maintained Buildings with a single staircase (provided compartmentation is adequate) NOT appropriate for: Buildings with known cladding defects Buildings with compromised compartmentation Converted buildings with inadequate fire separation Buildings where fire risk assessment identifies deficiencies Simultaneous Evacuation Principle: All occupants evacuate immediately when the alarm sounds. Relies on: Building wide fire detection and alarm system (L1 or L2 to BS 5839 1) Adequate staircase capacity for full building evacuation Clearly signed and maintained escape routes Emergency lighting throughout Appropriate for: Commercial buildings (offices, retail) Hotels and guesthouses Residential buildings where stay put cannot be maintained Small residential buildings (typically under 4 storeys) Any building where compartmentation is compromised Phased Evacuation Principle: Evacuation occurs in phases — fire floor first, then adjacent floors, then remaining floors. Relies on: Sophisticated voice alarm system with phased messaging Fire control room with trained operators Adequate staircase capacity for phased movement Enhanced structural fire protection Typically requires sprinkler protection Appropriate for: Large complex buildings (hospitals, shopping centres) High rise commercial buildings Buildings with vulnerable occupants who need additional time Buildings where simultaneous evacuation would overwhelm escape routes The Impact of Post Grenfell Changes The Grenfell Tower fire fundamentally challenged the stay put strategy. Key changes include: 1. Fire Safety (England) Regulations 2022 require building owners to prepare Evacuation Plans and share them with the fire service 2. Building owners must install wayfinding signage in buildings over 11m 3. Electronic information boxes must be provided in buildings over 18m 4. The concept of a temporary change from stay put to simultaneous evacuation is now explicitly recognised 5. Fire and rescue services now prepare building specific operational plans for high rise buildings Making the Right Decision The evacuation strategy should be determined by: 1. The building's physical characteristics (height, layout, staircase provision) 2. The condition of fire safety systems (particularly compartmentation) 3. The occupant profile (age, mobility, vulnerability) 4. The use of the building (residential, commercial, mixed) 5. Firefighting access and facilities available Critically, the strategy must be reviewed whenever significant changes occur — and the fire risk assessment must confirm that the building can support the chosen strategy. For expert evacuation strategy advice, contact Magnus Opifex.