An EWS1 form (External Wall Fire Review) is a certificate used to confirm the fire safety of external cladding and wall systems on some residential buildings, most often blocks of flats above a certain height or with specific cladding types.
Mortgage lenders sometimes request an EWS1 form before agreeing to lend on a flat in a building where the external wall materials need to be checked, and the rating given on the form (ranging from A1, the safest classification, through to B2, which indicates remedial work is needed) can directly affect whether a lender is willing to proceed and on what terms. Not every building requires an EWS1 form — it depends on height, cladding type and other building-specific factors — so it’s worth checking with the freeholder or managing agent, and with your broker, early in the buying process if you’re purchasing a flat.