The EWS1 form — External Wall System form — is a fire-safety certificate for the external walls of a residential block. It was introduced by the RICS and UK Finance in December 2019 in response to mortgage lender concerns after the Grenfell Tower fire, and has become a defining document for the saleability of many UK flats.
Without a valid EWS1, many flats cannot be mortgaged. With one, mortgage access depends on the grade the form assigns.
When an EWS1 is needed
The form applies to blocks of flats and is usually requested by a buyer’s mortgage lender when:
- The building is over 18 metres (roughly 6 storeys or more) — strict requirement.
- The building is 11 to 18 metres with cladding or combustible external features — often required.
- The building is under 11 metres — rarely required, but sometimes requested where there are specific concerns.
If a lender requires an EWS1 and the building doesn’t have one — or has one with a concerning grade — the mortgage is typically declined. The sale then stalls until the building is certified, or collapses.
EWS1 grades
An EWS1 form issued by a qualified assessor records one of several grades:
- A1 — materials of limited combustibility. No remediation needed.
- A2 — some combustible materials but risk is low. No remediation needed.
- A3 — combustible materials but risk is low. No remediation needed, with justification.
- B1 — combustible materials with low risk such that remediation is not needed.
- B2 — combustible materials with high risk. Remediation required.
A1–A3 and B1 ratings typically allow mortgaging to proceed. A B2 rating often blocks mortgages on affected flats until the identified works are completed.
The practical effect on sales
EWS1 issues have made thousands of UK flats effectively unsellable on the open market between 2020 and 2026. Leaseholders have been caught in disputes between freeholders (who control the building), managing agents (who commission the surveys), and developers (who built the block). Remediation works funded under the Building Safety Act and the Cladding Safety Scheme are progressing, but many blocks are still in limbo.
If you’re selling a flat in an affected block:
- Ask your freeholder or managing agent for the building’s EWS1 status.
- Include the form (or its absence) in your LPE1 pack.
- Be realistic about buyer pool — mortgaged buyers may be excluded depending on grade.
- Consider a cash buyer — not subject to mortgage lender requirements.
Cash buyers and EWS1
A principal cash buyer is not constrained by mortgage lender EWS1 requirements. We can purchase flats in blocks with B2 ratings, blocks awaiting remediation, or blocks where the EWS1 has not yet been issued.
That said, we do factor the cladding situation into our offer. The uncertainty has real cost — a flat with unresolved cladding issues is worth less than one without — and we price that in transparently. When remediation is underway or complete, our offers move closer to full market value.
Related
- LPE1 form — the leasehold management pack that typically includes EWS1 status.
- Leasehold vs freehold — why EWS1 concerns sit with leaseholders.
- Cash buyer — the route when mortgaged sales are blocked.