Every building has a fire strategy, whether or not anyone wrote it down. The escape routes are a certain length for a reason. The compartment walls are where they are for a reason. The alarm is a particular category for a reason.
A fire strategy document is the record of those reasons. This explains what it is, what it contains and why buildings without one cause problems for decades.
The definition
A fire strategy is an engineering design document setting out how a building is designed to achieve fire safety and demonstrating that the design satisfies the functional requirements of Part B of Schedule 1 to the Building Regulations 2010.
It is a design-intent document. It says what the building is supposed to do in a fire, why the designers believe it will do that and what the building's operators must do to keep it true.
That last element is the one most people miss and it is the reason a fire strategy remains relevant for the life of the building rather than being filed after practical completion.
The five functional requirements it addresses
Part B of Schedule 1 sets out five requirements. A fire strategy is structured, directly or indirectly, around them:
- B1 Means of warning and escape: the building must be designed and constructed so that there are appropriate provisions for early warning of fire and appropriate means of escape to a place of safety outside the building, capable of being safely and effectively used at all material times
- B2 Internal fire spread (linings): to inhibit the spread of fire within the building, the internal linings must resist the spread of flame and, if ignited, have a rate of heat release or fire growth reasonable in the circumstances
- B3 Internal fire spread (structure): the building must be designed and constructed so that stability is maintained for a reasonable period, with provisions for compartmentation, cavities and concealed spaces
- B4 External fire spread: external walls and roofs must resist the spread of fire over them and from one building to another
- B5 Access and facilities for the fire service: the building must be designed and constructed to provide reasonable facilities to assist firefighters in protecting life
Everything in a strategy ultimately points back to one of those five.
What a fire strategy contains
The structure varies with the building but a competent strategy will cover the following.
1. Scope, basis of design and design approach
The most important section and the one that is most often thin.
It should state which route to compliance has been taken:
- Prescriptive compliance with Approved Document B, following the guidance directly
- A code-based approach using BS 9991:2024 for residential buildings or BS 9999:2017 for buildings other than dwellings, which allow greater design flexibility in return for a structured assessment of risk
- Fire engineering under BS 7974, using performance-based analysis where the design departs from both
It should also state which guidance version applies, the design occupancy and any assumptions being carried through the rest of the document.
Where BS 9999 is used, this section should establish the risk profile, being the combination of the occupancy characteristic and the fire growth rate. BS 9999 defines occupancy characteristics as A for occupants awake and familiar with the building, B for occupants awake and unfamiliar, C for occupants likely to be asleep and D for occupants receiving medical care, which is outside the standard's scope. Fire growth rates run from 1 slow to 4 ultra-fast. Combining them produces a risk profile such as A2, B3 or C1 and that profile then drives travel distances, exit widths, fire resistance periods and much else.
Note that BS 9999 treats profiles A4, B4 and C4 as unacceptable within its scope unless sprinklers or an effective localised suppression system are added, which reduces the fire growth rate by one category.
2. Building description
Use and purpose group, number of storeys above and below ground, height to the top storey, floor areas, construction and any features that materially affect fire safety such as atria, basements, mezzanines or open-plan arrangements.
3. Occupancy
Design occupant numbers by floor and by area, occupancy characteristics and the presence of occupants who may need assistance to evacuate. This is the input that drives exit capacity and it is the input that most often turns out to be wrong later when the building is actually used.
4. Evacuation strategy
Which strategy applies and where:
- Simultaneous evacuation
- Phased evacuation
- Progressive horizontal evacuation, typical in hospitals and care homes
- Stay put or defend in place, typical in purpose-built blocks of flats
- Delayed or staged alarm arrangements
The strategy must state what the evacuation approach depends on because that is what the building's operators must sustain.
5. Means of escape
Travel distances in one and more than one direction, exit widths and capacities, number and location of stairs, protected corridors and lobbies, dead ends, inner rooms, final exits, external escape routes, refuges and evacuation lifts and provision for disabled occupants.
6. Compartmentation and structural fire protection
Compartment lines and their fire resistance periods, separating construction, protected shafts, cavity barriers, fire stopping at service penetrations and the fire resistance of the loadbearing structure.
This section is the one that matters most over the building's life because it is what future alterations threaten.
7. Fire detection and alarm
System category and design standard, detection coverage, alarm devices, zoning, interfaces with other systems and how the system supports the evacuation strategy. In a stay put block, for example, the strategy should explain why there is no communal alarm and what that depends on.
8. Suppression
Sprinklers, water mist or other systems: where provided, to which standard and critically, what the design relies on them for. If sprinklers are the reason a travel distance is longer than Approved Document B would allow, that must be stated. Otherwise a future duty holder may treat them as a discretionary extra.
9. Smoke control
Natural or mechanical, the areas served, design intent and expected performance. Where smoke control is engineered rather than prescriptive, the modelling basis should be summarised and the full analysis appended.
10. External fire spread
Boundary distances, unprotected areas, external wall construction and reaction to fire classifications, roof coverings, balconies and attachments.
Note that regulation 7(2) requires that in relevant buildings with a storey at least 18 metres above ground level containing dwellings, an institution or a room for residential purposes, materials becoming part of an external wall or specified attachment achieve class A2-s1, d0 or class A1, other than items exempted by regulation 7(3).
Note also that on a material change of use, regulation 6(1)(c) applies requirement B4(1) to buildings exceeding eleven metres in height, a threshold reduced from 18 metres with effect from 1 December 2022.
11. Fire service access and facilities
Vehicle access routes, hardstanding, hydrants, firefighting shafts, firefighting lifts and stairs, dry or wet fire mains and information provision for the fire and rescue service.
12. Departures and justifications
Every departure from prescriptive guidance, with the engineering justification, the compensatory features relied on and any modelling that supports it.
This is the section building control reads first and the section that determines whether an application is approved or rejected.
13. Management requirements and assumptions
What the strategy assumes the building operator will do. Staff numbers and training for a phased evacuation. Maintenance of compartmentation. Keeping escape routes clear. Sprinkler servicing. Housekeeping in a high fire load area.
BS 9999 devotes a full section to designing for the management of fire risk and defines management levels associated with each risk profile. A design that assumes a high standard of management and is handed to an operator who does not know that is a design that will fail quietly.
The standards behind it
| Document | Scope |
|---|---|
| Approved Document B, Volume 1 | Dwellings |
| Approved Document B, Volume 2 | Buildings other than dwellings |
| BS 9991:2024 | Fire safety in the design, management and use of residential buildings |
| BS 9999:2017 | Fire safety in the design, management and use of buildings, other than dwellings |
| BS 7974 | Application of fire safety engineering principles to the design of buildings |
Approved Document B is guidance, not law. Approved Document B itself is clear that following the guidance does not guarantee compliance and that it may not provide appropriate guidance where a case is unusual in terms of design, setting, use, scale or technology. It lists non-standard conditions including buildings with unusual occupancies or high complexity, very large or very tall buildings, large timber buildings and some buildings using modern methods of construction.
The legal duty is to satisfy the functional requirements. The strategy is how you demonstrate that you have.
Why it matters after handover
Three reasons.
Regulation 38. Where building work consists of or includes the erection or extension of a building to which the Fire Safety Order applies or is carried out in connection with a relevant change of use, the person carrying out the work must give fire safety information to the responsible person, no later than completion or first occupation, whichever is earlier. Approved Document B states the aim is achieved when the responsible person has all the information needed to understand and implement the fire safety strategy, maintain the fire safety systems and carry out an effective fire risk assessment. It states expressly that where a fire strategy has been prepared, it should be made available to the duty holder.
Since 1 October 2023 there is also a closed loop: the responsible person must acknowledge receipt in writing and confirm the information is sufficient and the person carrying out the work must notify the relevant authority that this has happened, within tight timescales.
The fire risk assessment depends on it. The first of the nine steps in PAS 79-1:2020 and BS 9792:2025 is obtaining information about the building, including the fire strategy where a documented one exists. BS 9792:2025 notes that other than in small, simple premises, the strategy is likely to be of value to the assessor.
Alterations. Every future alteration needs to be checked against the strategy. Without it, nobody knows whether the wall they are about to remove is a compartment wall or whether the sprinklers they are about to decommission were compensating for something.
What a fire strategy is not
It is not a fire risk assessment. The strategy is design intent. The assessment evaluates operational risk in a building in use. See our separate guide on the difference.
It is not a set of drawings. Fire strategy drawings are part of it but the reasoning is the document.
It is not a compliance certificate. It is an argument. Building control decides whether the argument holds.
It is not fixed forever. It should be updated when the design changes during the project and revisited when the building changes afterwards.
Frequently asked questions
What is the difference between a fire strategy and fire strategy drawings? Drawings show compartment lines, escape routes, fire door locations and the position of fire safety equipment. The strategy document explains the reasoning, the standards applied, the assumptions made and the departures justified. Drawings without the document leave you unable to explain anything.
Who writes a fire strategy? A fire engineer or fire safety designer. Where the design relies on performance-based fire engineering under BS 7974, it requires a suitably qualified fire engineer, typically chartered.
Is Approved Document B legally binding? No. It is statutory guidance supporting the functional requirements in Part B of Schedule 1. Following it is one way of demonstrating compliance. The legal duty is to satisfy the requirements themselves.
What is a risk profile in BS 9999? A combination of the occupancy characteristic, being whether occupants are awake or asleep and familiar or unfamiliar with the building and the fire growth rate, from slow to ultra-fast. The resulting profile, such as A2 or B3, determines the design parameters.
Can a fire strategy be a few pages? For a small simple building, yes. Length should be proportionate. What cannot be short is the reasoning behind any departure from prescriptive guidance.
We have never had one. Does that matter? For an existing occupied building, it matters most when you come to alter it, sell it, refinance it or defend a fire risk assessment finding. See our guide on retrospective fire strategies.
