What the EWS1 form does
The External Wall System 1 form was created by the industry to give mortgage lenders a consistent way to assess fire risk in the external walls of multi-storey, multi-occupancy residential buildings. A suitably qualified professional inspects the cladding and wall construction and assigns a rating.
It is important to understand that the EWS1 is a lending and valuation tool, not a safety certificate the building must legally hold. It exists so that surveyors can value flats and lenders can lend with confidence. One form covers the whole building and lasts five years.
What the EWS1 ratings mean
The form uses two categories, A and B, with numbered subcategories.
| Rating | Meaning | Typical lending impact |
|---|---|---|
| A1 | Materials unlikely to support combustion | Usually acceptable to lenders |
| A2 | Low risk, no remedial work needed | Usually acceptable |
| A3 | Combustible materials but low risk overall | Often acceptable, may need conditions |
| B1 | Fire risk low enough, no remediation required | Usually acceptable |
| B2 | Remediation required to manage the fire risk | Lending often paused until works done |
A B2 rating does not mean the flat is unsafe to live in, but it signals works are needed, which affects mortgage decisions.
What flat buyers should check
- Whether the building needs an EWS1 form for your lender.
- The EWS1 rating, A grades and B1 generally pass, B2 may require works.
- Who is responsible for any remediation costs.
- Whether leaseholder protections under the Building Safety Act apply.
- Service charge or insurance increases linked to fire safety.
- Whether the developer has signed a remediation pledge for the building.
Who typically pays for remediation
| Party | When they may be liable |
|---|---|
| Developer | Where they built the building and signed the remediation contract or pledge |
| Building owner / freeholder | Where they meet the net-worth tests under the Building Safety Act |
| Government schemes | For eligible buildings via dedicated cladding funds |
| Leaseholders | Capped or excluded for many qualifying leaseholders under the Act |
Qualifying leaseholders are protected from most or all cladding-remediation costs, but eligibility depends on the building and lease.
One form covers the building
An EWS1 form applies to the whole building and lasts five years, so an existing valid form may already be available from the freeholder or managing agent. Ask for it before paying for a fresh assessment.
Why fewer flats now need an EWS1
Government and industry guidance has reduced the number of buildings where an EWS1 is expected, particularly for lower-rise blocks without obvious combustible cladding. Many major lenders updated their criteria so that buildings below a certain height, or with no relevant external wall materials, no longer require the form.
Even so, requirements still vary by lender and building, so the safest approach is to ask the managing agent whether a valid form exists, and confirm with your lender or broker what they need, before you commit time and money to a purchase.