The short answer
An EWS1 form (External Wall System 1) is a standard form used to record the outcome of a fire safety assessment of the external walls of a building containing flats, mainly to help mortgage lenders and valuers decide whether a flat can be lent against. It is completed by a suitably qualified professional (such as a chartered fire engineer) and covers the whole building's external wall, so one form serves all the flats in a block. It is generally needed for flats in buildings over 11 metres in height where a lender requires it, and it is not designed for, and generally not needed for, individual houses. An EWS1 is a valuation aid, not a Building Regulations approval or a safety certificate, and it lasts five years.
EWS1 is widely misunderstood, especially by house owners. This page explains what it is, the height threshold, why houses are different, and what the form does and does not certify.
EWS1 at a glance
- What it isexternal wall fire review form
- Purposemortgage valuation aid
- Applies toflats / blocks, often over 11m
- Not forindividual houses (generally)
- Valid forfive years per building
What the EWS1 form is for
The EWS1 form was introduced by RICS, lenders and others to give mortgage valuers a consistent way to record the fire safety position of a building's external wall system — the cladding and the materials behind it. After concerns about combustible cladding on residential blocks, lenders began asking for evidence about external walls before lending on flats. The EWS1 provides that evidence in a standard format: a qualified professional assesses the external wall and records the outcome on the form. Importantly, it relates to the whole building, so a single EWS1 covers every flat in the block — an individual leaseholder does not need their own. It is valid for five years for the building.
When an EWS1 is needed — and when it is not
An EWS1 is essentially a lender-driven requirement, not a legal one for the building itself. Whether it is needed depends on the building and the lender:
- It is generally relevant for flats in buildings over 11 metres in height, and RICS guidance helps identify when a form is and is not needed below that.
- It is typically requested when a flat is being bought, sold or remortgaged and the lender wants assurance about the external walls.
- It is not designed for individual houses — owners of standalone, semi-detached or terraced houses generally do not need an EWS1, and lenders do not usually ask for one.
- Lower-rise blocks may not need one depending on the materials and the RICS criteria.
If you own a house and are asked for an EWS1, it is worth checking, because the form was not intended for houses.
| Property type | EWS1 usually needed? | Note |
|---|---|---|
| Individual house | no | form not designed for houses |
| Flat in block over 11m | often, if lender requires | one form per building |
| Flat in lower block | sometimes | depends on RICS criteria / materials |
| New-build with sign-off | may not need | depends on documentation |
Indicative guidance; whether a form is required depends on RICS criteria and the specific lender.
Who completes it and what it certifies
The EWS1 must be completed by a suitably qualified and competent professional, such as a chartered fire engineer or other professional with the relevant expertise, who takes responsibility for the assessment. The form records an outcome category for the external wall system. Crucially, an EWS1 is not a Building Regulations completion certificate, a safety certificate, or a guarantee that a building is safe — it is a snapshot to support mortgage valuation. It also does not, by itself, require or fund any remediation; where an assessment identifies issues, addressing them is a separate matter for the building owner and the responsible professionals. The form simply communicates the assessed position to lenders and valuers in a recognised format.
What house owners should know
The single most useful point for visitors to a house-cladding site is that EWS1 generally does not apply to individual houses. The form exists because lenders needed assurance about multi-occupancy residential blocks, particularly taller ones, where many homes sit behind a shared external wall and where escape and fire spread are more complex. A standalone house does not raise the same valuation question. If you own a flat in a block, the EWS1 is handled at building level by the building owner or managing agent, who should hold or arrange the form — you should ask them rather than commission your own. If you are unsure whether your specific property needs one, your conveyancer, lender or a competent professional can advise.
Frequently asked questions
Does a house need an EWS1 form?
Generally no. The EWS1 form was designed for buildings containing flats, particularly blocks over 11 metres, to support mortgage valuation. Individual houses — detached, semi-detached or terraced — do not normally need one, and lenders do not usually ask for an EWS1 on a house.
Is an EWS1 form a safety certificate?
No. It is a tool to help mortgage lenders and valuers, not proof that a building is safe or Building Regulations compliant. It records the assessed position of the external wall system. Genuine fire safety concerns are handled through the building's fire risk assessment and competent professionals.
How long does an EWS1 form last?
An EWS1 is valid for five years for the building it covers, and it applies to the whole building rather than an individual flat. After five years, or if significant changes are made to the external wall, a new assessment may be needed. The building owner or managing agent normally holds it.
Sources & further reading
Figures on this page are typical UK ranges drawn from published sources and depend on your specific property. They are guidance, not a quotation.