PAS 9980 and water mist: what leaseholders and flat owners need to know
If you own or manage a flat in a multi-storey building, you may have heard the terms PAS 9980 or FRAEW in letters from your managing agent, or when trying to sell or remortgage.
PAS 9980:2022 is the code of practice used to assess the fire risk from the external walls and cladding of existing blocks of flats. The assessment, known as a FRAEW, decides whether a building needs remediation or other safety measures, and internal fire suppression such as sprinklers or water mist is one of the measures an assessor can consider.
In this guide, we will explain what PAS 9980 means for your property, what happens if your building is rated high risk, and the questions to ask your managing agent or freeholder.
What is PAS 9980?
PAS 9980:2022 was published by the British Standards Institution (BSI) in 2022, giving safety professionals a step-by-step method for deciding whether a multi-occupied residential building’s external walls put residents at an acceptable risk of fire.
The standard covers purpose-built blocks of flats, as well as student accommodation, sheltered housing and buildings converted into flats.
Before PAS 9980, many buildings were judged against blanket government advice that treated almost any combustible material in a wall as unacceptable. PAS 9980 replaced this with a risk-based approach, which asks how much risk the walls actually pose in that particular building and what would make that risk acceptable.
What is a FRAEW?
A FRAEW, or Fire Risk Appraisal of External Walls, is the assessment carried out using the PAS 9980 method. The assessor examines how the walls are built, often opening up sections to see behind the cladding, and considers several risk factors, including:
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- The fire performance of the materials in the wall, such as insulation and cladding panels
- How the outside of the building is put together, including balconies and windows
- The fire safety measures already inside the building, such as alarms and sprinklers
- How residents would evacuate and how the fire service would access the building
- The height of the building
- The assessment then generates a risk rating. A low rating means the risk is acceptable and no action is needed on the walls, medium means the risk is tolerable but could be improved, and high means significant changes are needed.
How is PAS 9980 different from an EWS1 form?
PAS 9980 and EWS1 are often confused, but they do different jobs.
A FRAEW using the PAS 9980 method is a life safety assessment that tells the building’s Responsible Person whether the external walls pose an acceptable risk to residents, whereas an EWS1 form is a valuation document, administered by RICS, that mortgage lenders use when deciding whether to lend on a flat.
A thorough FRAEW can provide the evidence needed for an EWS1 form, but they aren’t interchangeable indicators of fire safety.
What happens if your building needs remediation?
If a FRAEW rates your external walls as high risk, the Responsible Person for the building must make changes to improve the fire risk in the building.
In practice, this means putting interim measures in place, such as a waking watch or temporary fire alarm, and then deciding between full remediation to remove and replace unsafe materials or mitigation measures that bring the risk down to an acceptable level.
Remediation can take years to fund and complete, and a waking watch is expensive to keep running, which is why the choice of longer-term measures can often matter more to leaseholders.
Where does water mist fit in?
PAS 9980 considers the fire safety measures inside a building as part of the overall risk, and it recognises sprinklers in flats as a possible mitigation measure. This is because controlling a fire in the flat where it starts makes it far less likely to grow large enough to break windows and reach the external wall.
However, it’s also important to be realistic, as a suppression system can’t control a fire that starts outside the building, or one that is already spreading within the wall, so it doesn’t remove the need to deal with a high-risk wall altogether.
Residential water mist systems work on the same principle as sprinklers, and how much weight an assessor gives them depends on the evidence available. iMist is certified to BS EN 14972-17:2025, the current UK standard for residential water mist, tested as a full system at the Fire Protection Association’s UKAS-accredited facility.
Where suppression forms part of the solution, water mist offers practical advantages for occupied buildings. It can be fitted flat by flat while residents stay at home, flexible pipework means minimal disruption to ceilings, and low water use limits damage to flats below if the system is ever activated.
What to ask your managing agent or freeholder
As a leaseholder, you’re entitled to clear information about the fire safety risk in your building.
These six questions will help you understand where things stand, and where improvements are needed:
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- Has a FRAEW been carried out to PAS 9980, and when?
- Who carried it out?
- What risk rating did the external walls receive?
- Were mitigation options considered, including sprinklers or water mist inside the flats?
- What interim measures are in place, and how long will they last?
- What is the timetable for remediation or mitigation?
Discover how iMist can safeguard your building
If you manage a multi-occupancy building and would like to discuss fire suppression as part of your mitigation strategy, contact our team today.
Frequently asked questions
Is PAS 9980 a legal requirement?
PAS 9980 is a code of practice, not law. However, it’s the recognised method for assessing external wall fire risk in existing blocks of flats in England, and the Responsible Person’s legal duty to assess fire risk now explicitly covers external walls.
Does a high-risk FRAEW mean my building is unsafe to live in?
A high-risk rating doesn’t necessarily mean that your building is immediately unsafe to live in. The risk rating indicates that your external walls need remediation, but the Responsible Person should review the fire risk assessment, put interim measures in place where needed and plan longer-term works.
Can sprinklers or water mist replace cladding remediation?
Water mist systems like iMist can reduce the need for cladding remediation, but they rarely replace the risk entirely.
Suppression lowers the chance of a fire inside a flat spreading to the external wall, helping to support lower risk ratings, but it can’t control a fire that starts outside or is already spreading in the walls.
Does PAS 9980 only apply to buildings over 18 metres?
No, PAS 9980 is risk-based and can apply to multi-storey, multi-occupied residential buildings of different heights. Building height is one of the risk factors the assessor considers, but other factors are also taken into account when carrying out a FRAEW.