PAS 9980: External Wall Fire Risk Assessment Guide

PAS 9980:2022 is the BSI-published code of practice for assessing the fire risk of external wall construction. It was developed in response to the Grenfell Tower disaster and the subsequent need for a standardised methodology to evaluate external wall systems on existing buildings.

If you carry out standard fire risk assessments under PAS 79 and are encountering buildings where external wall fire risk is a concern, here is what you need to know about PAS 9980 and how it intersects with your work.

What PAS 9980 Covers

PAS 9980 provides a methodology for assessing the fire risk posed by external wall systems — specifically the combination of cladding, insulation, cavity barriers, fire-stopping, and the interaction between these components.

It applies to:

• Residential buildings of any height where there are concerns about external wall fire performance
• Buildings where an EWS1 (External Wall System) form is required for mortgage or insurance purposes
• Any building where a fire risk assessor or building safety manager has identified external wall construction as a risk factor

PAS 9980 is not a pass/fail test. It is a risk-based assessment that results in a fire risk rating for the external wall system, ranging from negligible to intolerable.

How PAS 9980 Relates to PAS 79

PAS 79:2020 is the standard for whole-building fire risk assessment. Since the Fire Safety Act 2021 brought external walls explicitly into scope (see our Fire Safety Act guide), your PAS 79 assessment should include observations about external wall construction.

The relationship works like this:

1. During your PAS 79 assessment, you observe and record the external wall construction: cladding type, insulation (if visible), condition, and any concerns.
2. If you identify concerns — aluminium composite cladding, combustible insulation, missing cavity barriers — you recommend that the responsible person commissions a PAS 9980 assessment.
3. The PAS 9980 assessment is a specialist piece of work, typically carried out by a fire engineer or external wall specialist, not a standard fire risk assessor.

Your PAS 79 assessment flags the concern. The PAS 9980 assessment investigates it in depth. They are complementary, not competing.

Scope of a PAS 9980 Assessment

A PAS 9980 assessment includes:

• Desktop study. Review of building plans, construction records, previous fire risk assessments, and any available information about the wall system.
• Visual inspection. External examination of the wall system, looking for: cladding type and condition, evidence of compartmentation at floor/party wall junctions, condition of cavity barriers, weathering or deterioration.
• Intrusive investigation (if needed). Opening up sections of the wall to inspect insulation, cavity barriers, and fire-stopping. This is a destructive investigation — it requires access equipment and contractor support.
• Fire engineering analysis. Assessment of the wall system's fire performance against the applicable standards and building regulations that were in force when the building was constructed or last refurbished.
• Risk rating. The assessor assigns a fire risk rating to the external wall system, considering the likelihood of fire spread via the external wall and the consequences for occupants.

Competence Requirements

PAS 9980 assessments require specialist competence beyond standard fire risk assessment qualifications. The BSI document specifies that assessors should have:

• Relevant fire engineering or fire safety qualifications
• Specific knowledge of external wall construction and fire performance
• Experience in intrusive investigation of external wall systems
• Understanding of building regulations as they apply to external walls

If you are a PAS 79 fire risk assessor without this specialist background, you should not carry out PAS 9980 assessments yourself. Your role is to identify the need and recommend appropriate specialist input.

Buildings Affected

PAS 9980 is most relevant to:

• High-rise residential buildings (18m+). These have been the primary focus since Grenfell. Many have undergone remediation programmes, but some still require assessment.
• Medium-rise residential buildings (11-18m). The Building Safety Act 2022 extended building safety requirements to buildings over 11m. External wall assessments are increasingly required at this height.
• Any building with known cladding concerns. Aluminium composite material (ACM) cladding, high-pressure laminate (HPL) cladding, and certain types of insulation have been identified as fire risks regardless of building height.

EWS1 Forms and Mortgage Implications

The EWS1 form (External Wall System Fire Review) was introduced by the Royal Institution of Chartered Surveyors (RICS) as a standardised way for mortgage lenders to assess external wall fire risk. A PAS 9980 assessment can inform the completion of an EWS1 form, but the two are not the same thing.

EWS1 has two options:

• Option A: An external wall system assessment is not needed (no combustible materials or adequate risk mitigation)
• Option B: An external wall fire risk assessment is needed, with ratings from B1 (no remediation required) to B2 (remediation required)

A B2 rating can affect property sales and mortgage availability. This is the commercial pressure that drives many PAS 9980 assessments.

What Fire Risk Assessors Should Do

During your standard PAS 79 fire risk assessments on residential buildings:

1. Record the external wall construction. Note the cladding type (if identifiable), insulation type (if visible), and general condition.
2. Look for obvious concerns. Combustible cladding materials, missing or damaged sections, evidence of previous remediation work, balcony construction.
3. Check documentation. Ask the responsible person whether a PAS 9980 assessment or EWS1 form has been completed. Note the results in your report.
4. Recommend specialist assessment where needed. If you have concerns about the external wall system that are beyond your competence to evaluate, recommend that the responsible person commissions a PAS 9980 assessment.

Summary

PAS 9980 is the specialist methodology for external wall fire risk assessment. As a PAS 79 fire risk assessor, your job is to observe, record, and flag external wall concerns — not to carry out the full PAS 9980 assessment yourself. Know when to recommend it and what it involves so you can advise your clients properly.

For guidance on the broader scope changes affecting residential assessments, see our Fire Safety Act 2021 guide. For PAS 79 assessment methodology, see our section-by-section guide.

AssessKit is being built with external wall observation fields integrated into the PAS 79 assessment workflow — record what you see, flag concerns, and recommend specialist assessment where needed. Join the waitlist for early access.

Sources

• PAS 9980:2022 — Code of practice for fire risk appraisal of external wall construction — BSI
• Fire Safety Act 2021 — UK Legislation
• Building Safety Act 2022 — UK Legislation