PAS 9980 Explained: What a Fire Risk Appraisal of External Walls Actually Involves
PAS 9980 is the Publicly Available Specification that gives UK fire engineers a common methodology for assessing the fire risk of the external walls of existing multi-storey residential buildings. It was published by BSI in 2022 and is now the default approach freeholders, managing agents and lenders expect when appraising a building's facade.
This guide explains what PAS 9980 covers, what a Fire Risk Appraisal of External Walls (FRAEW) actually involves, the outcomes it produces, and how those outcomes drive the remediation scope.
What PAS 9980 Covers
PAS 9980 applies to existing multi-storey (typically 4+ storeys) residential and mixed-use buildings — not new-build. It gives a structured methodology for a competent fire engineer to appraise:
- —The materials in the external wall build-up (cladding, insulation, membranes, cavity barriers)
- —The geometry and detailing of the facade (cavity depths, openings, balconies, junctions)
- —The mitigating features present (sprinklers, evacuation strategy, compartmentation)
- —The overall risk that a fire starting inside or outside could spread up or across the facade
The FRAEW Methodology
A FRAEW under PAS 9980 is a three-stage process:
Stage 1 — Desktop review
The engineer gathers construction records, previous surveys, EWS1 forms, warranty documentation and any as-built information. Where records are incomplete (which is almost every existing building), Stage 2 fills the gaps.
Stage 2 — Intrusive investigation
Opening-up surveys at representative locations across the facade confirm what's actually built. Samples of cladding, insulation and cavity barriers are extracted and — where classification isn't documented — sent for testing. Cavity barriers are inspected for presence, continuity and installation quality.
Stage 3 — Risk appraisal and rating
The engineer weighs the materials, geometry and mitigations against the fire scenarios PAS 9980 sets out, and rates the overall risk of the external wall as Low, Medium or High. The rating carries a recommended action — from 'no action required' through 'management measures' to 'remediation'.
What the Outcomes Mean
| Rating | Typical outcome |
|---|---|
| Low | No remediation required. Standard building management continues. |
| Medium | Interim management measures (e.g. waking watch, evacuation strategy review) plus targeted remediation of specific issues. |
| High | Remediation of the external wall — usually strip-back and re-clad — to reduce the risk to Low or Medium. |
How FRAEW Outcomes Drive Remediation
Where the FRAEW recommends remediation, the fire engineer produces a specification setting out what must be removed, what must be installed in its place, and the fire classification the new build-up must achieve. That specification is what a competent facade remediation contractor tenders and installs against — typically A1 or A2-s1,d0 rainscreen, continuous cavity barriers at every slab edge, and full golden-thread documentation.
Frequently Asked Questions
Is a PAS 9980 FRAEW the same thing as an EWS1?
No. EWS1 is a single-page form for valuation purposes; PAS 9980 is the underlying methodology a fire engineer uses to reach the risk rating that populates the EWS1 (or drives a remediation programme).
Who can carry out a PAS 9980 FRAEW?
A competent fire engineer — typically a chartered engineer with facade fire experience. PAS 9980 sets competence requirements the appointed engineer must satisfy.
Does a High rating always mean the building is unsafe?
No — the rating is about the external wall's contribution to fire risk. A High rating means remediation is recommended, and interim management measures (evacuation plans, waking watch, alarms) usually keep the building safe to occupy in the meantime.