In short
- Many existing blocks have no usable fire strategy – lost, never written, or out of date after alterations.
- No single law demands one for every building, but it's often the clearest way to show fire precautions are adequate.
- Common triggers: an FRA action, a safety case, an insurer or lender, a sale, or planned works.
- A fire risk assessment is not a substitute – the two do different jobs.
What a retrospective fire strategy is
A retrospective fire strategy (sometimes called an existing building fire strategy) sets out how a building that's already built and occupied is intended to perform in a fire. It covers the evacuation strategy, means of escape, compartmentation, detection and alarm, smoke control, fire service access and facilities and the external walls – and compares what's actually there with the guidance that applied when it was built and with current expectations.
The key word is existing. A design fire strategy describes intent; a retrospective strategy describes reality, including the changes made over the years.
Why so many buildings don't have one
- It was never written. Older buildings often went through building control without a standalone strategy.
- It's been lost through changes of freeholder, managing agent or developer.
- It's out of date. Conversions, refurbishments, new services and alterations to flats have changed how the building works.
- Nobody trusts it. The document on file doesn't match the building.
Do I legally need one?
There's no single law that says every existing building must have a fire strategy. But under the Regulatory Reform (Fire Safety) Order 2005, the responsible person must show that adequate general fire precautions are in place – and that's hard to do if nobody can explain how the building is supposed to work in a fire.
For higher-risk buildings, the safety case report must explain how fire spread risks are managed, which in practice needs a clear fire strategy. The draft British Standard for fire strategies, BS 9994, also states that fire risk assessments are not substitutes for a fire strategy – see our guide to BS 9994.
Signs you need a retrospective fire strategy
- Your fire risk assessment recommends one, or keeps noting assumptions it can't verify – for example about compartmentation or the evacuation strategy
- You're preparing a safety case report for a higher-risk building
- An insurer, lender or buyer has asked for the fire strategy
- You're planning works that affect escape routes, compartmentation or alarm systems
- The building has been converted – for example from offices to flats
- There's uncertainty about whether the building should be stay put or simultaneous evacuation
What it contains
A good retrospective fire strategy typically includes:
- A review of the evidence – drawings, previous strategies, FRAs, FRAEWs, building control records and O&M manuals
- A site inspection of escape routes, compartmentation, fire doors, smoke control and fire service facilities
- An assessment against the relevant guidance – usually Approved Document B or BS 9991 for residential buildings, and BS 9999 for others
- An explanation of the evacuation strategy and whether it's still appropriate
- Departures from guidance – which are acceptable historic differences and which are genuine risks
- A prioritised action plan with clear responsibilities
- Fire strategy drawings that the FRA, the safety case and future works can rely on
Retrospective fire strategy vs fire risk assessment
A fire risk assessment checks how the building is being managed and maintained day to day – and it's a legal duty. A fire strategy explains how the building is designed to work in a fire. The FRA should be informed by the strategy; without one, the assessor has to make assumptions. Read more in fire strategy vs fire risk assessment.
How long it takes and what it costs
Most retrospective strategies take a few weeks from instruction, depending on the size of the building and how much information exists. Fees depend mainly on size, complexity and the state of the records – a building with good drawings costs less than one where the layout has to be surveyed. Where compartmentation is in doubt, a compartmentation survey is often carried out alongside.
What retrospective fire strategies often find
Every building is different, but these issues come up again and again:
- Stay put relying on unverified compartmentation – for example corridor walls that stop at the suspended ceiling
- Smoke ventilation that doesn't work, or no one knows how it's meant to work
- Alarm systems that don't match the evacuation strategy – such as common-area sounders in a stay put building
- Changes inside flats – open-plan layouts that remove the protected entrance hall
- Commercial units below flats with weaker separation than the flats need
- Fire service facilities – dry risers, firefighting lifts or access routes – that no longer meet expectations
Most findings are historic differences, not emergencies. A good retrospective strategy separates the two, so money goes to the issues that genuinely affect safety.
Our retrospective fire strategy service is delivered by qualified fire engineers, with a fixed fee confirmed before you instruct.
How we can help
We match each project to a qualified specialist and confirm the scope, the named professional and a fixed fee before you commit.
Sources
- News on the Block – Does your property have a retrospective fire strategy?
- FPA – Fire strategies standard consultation opens (BS 9994)
This guide is general information based on the law and guidance in England as at 8 November 2026. It isn't legal advice – for advice on a specific building, get in touch.