PAS 9980 in practice: proportionate external wall appraisal

PAS 9980:2022 is the British Standards Institution's publicly available specification for the fire risk appraisal of external wall construction and cladding of existing multi-storey, multi-occupied residential buildings — a process commonly referred to as a Fire Risk Appraisal of the External Wall (FRAEW). It was published in response to the external wall challenges that arose from the Grenfell Tower fire and the subsequent EWS1 (External Wall System) form process, and it provides a structured, risk-based methodology for assessing whether an external wall system presents an unacceptable level of fire risk.

The central premise of PAS 9980 is proportionality. The standard does not assume that any combustible material in an external wall is automatically unacceptable. It requires an assessment of the actual fire risk posed by the wall construction, taking into account all the factors that influence how a fire might develop and spread, and how the building's overall fire safety measures affect that risk. The output is a professional judgment about whether the risk is acceptable, and if not, what measures are needed.

What is PAS 9980, and what is a FRAEW?

In one sentence: a FRAEW — a fire risk appraisal of external walls — is the structured, evidence-based appraisal PAS 9980 defines: a competent professional's judgment on whether a building's external wall construction presents an acceptable level of fire risk and, where it does not, what should be done about it.

A FRAEW is not a substitute for the building's fire risk assessment; it sits alongside it. The Regulatory Reform (Fire Safety) Order 2005 requires the responsible person to have a suitable and sufficient fire risk assessment for the premises, and the Fire Safety Act 2021 confirmed that the external walls fall within its scope. A general fire risk assessment, however, rarely goes deep enough to reach a reliable judgment about external wall construction. Where the walls are a material consideration — cladding systems, combustible attachments, or construction whose fire performance is uncertain — the FRAEW is the specialist appraisal that resolves the question, and its conclusion feeds back into the fire risk assessment and, where one is required, the building's safety case.

What a FRAEW involves

A FRAEW is a structured desktop review and site inspection carried out by a competent assessor. The assessor reviews available information about the external wall construction — original design documents, as-built records, previous surveys, and any prior remediation work — and inspects the building to the extent needed to understand the construction.

The scope of the physical investigation will depend on how much reliable information exists. Where the wall construction is well documented, the site inspection may focus on confirming that the built form matches the records and identifying any subsequent alterations. Where the construction is unknown or poorly documented, more extensive investigation is needed — which may include opening up work to expose concealed construction.

The assessor then applies the PAS 9980 framework to arrive at a judgment about the risk. This involves assessing the fire performance of the wall components, the likely behaviour of the wall in a fire scenario, the effect of any cavity barriers and fire breaks, the building's overall height and layout, the evacuation strategy, and the fire and rescue service intervention capability. The judgment is recorded in an assessment report.

The proportionality principle in practice

One of the most important — and sometimes misunderstood — aspects of PAS 9980 is that an acceptable outcome is a legitimate and common result. The standard is not designed to trigger remediation on every building with any combustible material in its external wall. It is designed to distinguish between walls that present an acceptable level of risk (perhaps with some management measures) and those that present an unacceptable level of risk and require physical remediation.

A conclusion that a wall is acceptable as it stands — perhaps with enhanced management measures such as a waking watch arrangement during a defined period, or with increased inspection frequency — is a professional judgment that can be fully defensible. The key is that the judgment is evidence-based, clearly reasoned, and made by a competent assessor who has no commercial interest in the outcome.

This is where independence matters. An assessor who also provides remediation services has a structural commercial interest in recommending remediation. An independent assessor — one with no installation or remediation arm — can apply the standard to reach whatever conclusion the evidence supports, and that conclusion will carry greater weight with residents, insurers, lenders, and regulators.

What the assessment report should say

A PAS 9980 assessment report should clearly set out the scope of the investigation, the information reviewed, the site inspection findings, the assessor's analysis of the fire risk, and the overall conclusion. The conclusion should be expressed in terms of whether the external wall construction presents an acceptable or unacceptable level of risk, and if unacceptable, what remediation or interim management measures are recommended.

The report should also be clear about the limitations of the assessment — particularly where the investigation was constrained by limited information or access. A report that expresses high confidence in a conclusion based on limited information should be treated with caution. A good assessor will be explicit about uncertainty and about what additional investigation would reduce it.

The relationship between a FRAEW and an EWS1

The EWS1 form was introduced by UK Finance and the Royal Institution of Chartered Surveyors (RICS) as a way for lenders and conveyancers to confirm that an external wall assessment had been carried out on a building before a mortgage could be offered on a flat within it. The EWS1 form itself is not a technical standard — it is a declaration by a competent assessor as to whether the external wall construction requires further investigation or remediation, or whether it is acceptable.

PAS 9980 is now the recognised technical framework within which EWS1 assessments should be conducted. A properly conducted FRAEW under PAS 9980 provides the technical basis for completing an EWS1 form. Where a building requires an EWS1, a PAS 9980 assessment is the appropriate route to obtaining one.

Commissioning a proportionate appraisal

When commissioning a FRAEW, the responsible person should satisfy themselves that the assessor is competent — which means having the necessary fire engineering knowledge to understand external wall behaviour — and that the assessor is genuinely independent. Asking the assessor to confirm in writing that they have no commercial interest in any remediation outcome is a straightforward step that protects the integrity of the assessment.

The scope of the investigation should be agreed up front. A responsible person who commissions an assessment with an unrealistically narrow scope should not be surprised if the resulting report cannot reach a definitive conclusion. Investing in a thorough investigation upfront is almost always cheaper than having to commission additional work because the first assessment was inconclusive.

Apex's PAS 9980 survey service provides independent FRAEWs for residential buildings of all types. Because Apex holds no remediation or installation arm, every conclusion reflects the fire risk evidence rather than any downstream commercial interest.