PAS 79 methodology: how a structured fire risk assessment is carried out

PAS 79 ("Publicly Available Specification 79: Fire risk assessment — Guidance and a recommended methodology") is the British Standards Institution's guidance document setting out how a fire risk assessment should be structured and carried out. It isn't itself a legal requirement, but it is the recognised, industry-standard methodology that a competent assessment is expected to follow — and it gives clients a way of judging whether an assessment they've received is actually fit for purpose.

Why a standard methodology matters

Fire risk assessment is a judgement-based exercise — two competent assessors looking at the same building should reach broadly the same conclusions, but only if they're working to a consistent framework. Without one, the quality and thoroughness of an assessment depends entirely on the individual assessor's own habits, which makes it very difficult for a duty holder to know whether they're getting a genuinely thorough assessment or a superficial one. PAS 79 exists to close that gap.

The core structure

PAS 79 sets out a systematic sequence: identifying fire hazards (sources of ignition, fuel, and oxygen), identifying the people at risk and how vulnerable they are, evaluating the risk arising from those hazards, and considering the adequacy of existing fire precautions — means of escape, fire detection and warning, fire-fighting equipment, and the management of fire safety over time. The output is a structured record of significant findings, not a free-form narrative, which is what makes assessments carried out to PAS 79 comparable and auditable.

Risk rating, not just risk identification

One of the more important aspects of PAS 79 is that it doesn't stop at listing hazards — it provides a framework for rating the overall level of fire risk in a building (commonly expressed in bands such as trivial, tolerable, moderate, substantial, or intolerable), and for rating individual findings by priority. This is what allows an action plan to be genuinely prioritised, rather than presenting every finding as equally urgent.

What this means for you as a client

When you commission a fire risk assessment, asking whether it's carried out in line with PAS 79 is a reasonable and useful question — it tells you the assessor is following a recognised, structured methodology rather than an informal walk-round. It also means the resulting report should give you a clear risk rating for the building as a whole, not just a list of individual issues, and a genuinely prioritised set of actions rather than an undifferentiated checklist.

In practice

Every fire risk assessment we carry out follows the PAS 79 methodology, from initial hazard identification through to a risk-rated, prioritised action plan — because a structured approach is what turns an assessment into something you can actually act on, rather than a document that sits on a shelf.