Means of escape is the most fundamental fire safety requirement for any building. Here's how it works under UK regulations.
18 February 20254 min readFire Safety Services
What Are Means of Escape?
Means of escape are the routes by which occupants of a building can travel to a place of safety in the event of a fire — from the room of fire origin, through escape corridors and staircases, to a final exit and ultimate place of safety in the open air. The design and adequacy of means of escape is the most fundamental fire safety requirement for any building and is central to every fire strategy report.
UK building regulations require that every occupied building provides adequate means of escape for all occupants, taking into account the type of building, the number and characteristics of its occupants, the travel distances involved, and the available fire safety provisions. The applicable guidance depends on building type: Approved Document B for most buildings, BS 9991 for residential buildings, and BS 9999 for commercial buildings.
Travel Distance and Exit Capacity
Two of the most important parameters in means of escape design are travel distance and exit capacity:
Travel distance — the maximum distance a person should have to travel from any point in a building to reach a protected escape route or final exit. Travel distance limits vary by building type and occupancy. For most residential buildings, the maximum travel distance in a corridor to a protected staircase is 7.5 metres where there is only one direction of travel, and 30 metres where travel in two directions is possible.
Exit capacity — the width of escape routes and exits must be sufficient to allow all occupants to evacuate within an acceptable time. Staircase widths, door clear widths, and final exit widths are all specified in the applicable codes.
Note: Travel distance limits in UK codes assume the escape route is protected — that is, enclosed in fire-rated construction and smoke-sealed. Unprotected escape routes have more stringent limits.
Escape Routes in Residential Buildings
For purpose-built blocks of flats, the means of escape strategy is closely linked to the evacuation strategy:
Under a stay-put strategy, the escape route from each flat leads to a protected corridor or lobby, and from there to a protected staircase. The staircase leads to a final exit at ground floor. The escape route need only accommodate individual flat evacuations, not full building evacuation.
Under a simultaneous evacuation strategy, the escape routes must be capable of accommodating all occupants evacuating at the same time. This requires wider staircases, more exits, and careful management of convergence points.
For higher-risk residential buildings over 18 metres, BS 9991 requires a minimum of two staircases where the floor area exceeds a specified threshold, or where the building configuration means that a single staircase would be insufficient to safely evacuate occupants in the event of fire on the staircase or in a location that compromises its use.
Single Staircase vs Dual Staircase Buildings
The question of whether a tall residential building can safely be served by a single staircase has been the subject of significant debate following the Grenfell Tower fire. NFCC guidance published in 2023 recommends that buildings over 18 metres should have at least two staircases. The Building Safety Regulator and many local planning authorities have adopted this position for new higher-risk buildings.
For existing single-staircase buildings, the position is more nuanced. A fire engineering assessment considering the building height, number of flats per floor, evacuation strategy, and compartmentation integrity is required to determine whether the single staircase arrangement is acceptable or whether compensatory measures are needed.
Final Exits and Assembly Points
A means of escape is only complete when it leads to a final exit — a door from the building directly to a place of ultimate safety. Final exits must be clearly signposted, easily operable without a key, and positioned to allow occupants to move clear of the building without being impeded by fire service vehicles or smoke from the building. Assembly points should be identified and communicated to all occupants.
Frequently Asked Questions
What is the maximum travel distance to a fire exit?
Maximum travel distances depend on building type and whether travel in two directions is possible. For most residential buildings, the maximum single-direction travel distance in a corridor is 7.5 metres. For commercial buildings under BS 9999, limits are typically 18 metres (single direction) to 45 metres (two directions) depending on occupancy.
Does my building need more than one staircase?
For buildings over 18 metres, NFCC guidance and BSR expectations increasingly require at least two staircases. For lower buildings, the number of staircases required depends on floor area, occupancy, and the applicable code. A fire engineer can advise on the specific requirement for your building.
What width does a fire escape door need to be?
Minimum clear door widths depend on the number of people using the route. For most residential buildings, 750mm clear width is the minimum for escape doors. Wider widths are required for routes serving larger numbers of occupants.
Can escape routes pass through kitchens or other high-risk areas?
No. Means of escape must not pass through areas of high fire risk. Escape routes through kitchens, plant rooms, or storage areas are not acceptable. The escape route must be a protected path from the occupied area to a final exit.
What are the fire escape requirements for a block of flats?
For a typical block of flats, each flat must have a front door opening onto a protected corridor or lobby, leading to a protected staircase, which leads to a final exit. The corridor and staircase must be enclosed in fire-rated construction and the doors must be self-closing fire doors.
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