PAS 79-1, PAS 79-2 and BS 9792:2025 — Which Fire Risk Assessment Methodology Applies?
PAS 79 is the methodology behind most UK fire risk assessments. Since 2020 it has been split into a non-housing part and a housing part — and the housing part has since been replaced by BS 9792:2025. Here is which document should be on your report.
What PAS 79 is
PAS 79 is a Publicly Available Specification issued by BSI that sets out a methodology for carrying out a fire risk assessment. It is not a legal requirement — the duty to assess comes from the Regulatory Reform (Fire Safety) Order 2005 — but it is the recognised methodology, referenced by Fire Authorities, insurers and the courts.
The 2020 split, and what happened next
Until 2020, PAS 79 was a single document. The 2020 revision split it into two:
- PAS 79-1:2020 — Fire risk assessment, Part 1: Premises other than housing — Code of practice
- PAS 79-2:2020 — Fire risk assessment, Part 2: Housing — Code of practice
PAS 79-2:2020 was withdrawn on 6 August 2021 and, after a full revision, republished as a British Standard: BS 9792:2025, which came into effect on 31 August 2025 and expressly supersedes PAS 79-2. So today the pair is PAS 79-1 for premises other than housing and BS 9792:2025 for housing.
When PAS 79-1 applies
PAS 79-1 covers virtually all non-domestic premises:
- Offices, shops, restaurants and hotels
- Schools, universities and residential care homes
- Industrial and warehouse buildings
- Public assembly buildings
- Premises used solely for short-term letting
The methodology runs through a structured 9-step process from premises information to action plan.
When BS 9792:2025 applies
BS 9792:2025 covers fire risk assessments in housing premises and parts of housing premises. Its scope (Clause 1) lists:
- Houses in multiple occupation (HMOs)
- Blocks of flats or maisonettes — purpose-built and converted
- Specialised housing
- Student accommodation falling into any of those categories
- The areas that give access to residential accommodation in mixed-use buildings
It does not apply to a single private dwelling, to short-term lets, to non-domestic premises or to residential care homes — those go to PAS 79-1. The methodology addresses external walls (it does not replace a specialist PAS 9980 external-wall appraisal), flat entrance doors, and the stay-put versus simultaneous-evacuation decision, and it sits alongside the Fire Safety (England) Regulations 2022 duties for the same buildings.
Mixed-use buildings
For premises with both housing and non-domestic elements (shops on the ground floor with flats above, for example), competent assessors use both documents in parallel — PAS 79-1 for the commercial demise and BS 9792:2025 for the residential parts and the areas that give access to them.
What your assessor should reference
Any FRA report you receive should state which methodology was used. A report that cites only "PAS 79" is using a document that no longer exists in that form; a housing report that still cites PAS 79-2 is citing a document withdrawn in 2021. Either is a reason to ask questions before you rely on it.
All MetroFire FRAs are delivered to PAS 79-1 (premises other than housing) or BS 9792:2025 (housing) — or both, for mixed-use — by NFRAR-registered assessors. Book yours.
