What is an EWS1 form? A homebuyer's guide
Quick Summary
After the Grenfell Tower fire an EWS1 (External Wall System 1) form was introduced to help lenders and valuers assess the fire risk of external wall systems, including cladding. We’ve outlined everything you need to know about EWS1 forms and how to minimise the risk of it delaying a purchase.
Why does an EWS1 form matter when buying a flat?
An EWS1 form provides evidence to lenders that a building with potentially combustible cladding has received a fire safety assessment. Based on the fire risk assessment, the building will be assigned one of the following ratings:
Option A means the external wall materials are unlikely to support combustion:
A1 – no significant combustible cladding
A2 – cladding assessed and no remedial works required
A3 – materials are unlikely to support combustion but works may still be needed
Option B means combustible materials are present:
B1 – risk is low enough that remediation is not required
B2 – remedial work is required
Buyers of flats in buildings with a B2 rating will have fewer lending options than those in a B1 or A rated building. If this is discovered late in the purchase process, it can often lead to buyers dropping out of the purchase altogether as limited lending options can leave them unable to financially purchase the property.
In addition to the EWS1, your conveyancer may also require a FRA (Fire Risk Assessment) and FRAEW (Fire Risk Appraisal of External Walls), a Leaseholder Deed of Certificate and a Landlord’s Certificate. These documents help establish whether the leaseholder is protected from historical remediation costs and whether a lender is likely to proceed.
How long is an EWS1 valid?
One EWS1 generally covers the whole building and is normally valid for five years in England and Wales
What is the criteria for an EWS1?
Guidance from RICS (Royal Institute of Chartered Surveyors) suggests that the criteria for an EWS1 form will change from November 2026 to take into account the following:
| Building | RICS criteria for requesting an EWS1 |
|---|---|
| Over 6 storeys | Any cladding or curtain-wall glazing, or qualifying stacked combustible balconies |
| 5–6 storeys | A significant amount of cladding, or qualifying stacked combustible balconies |
| Less than 4 storeys | A significant amount (around 25% or more) of ACM (Aluminium Composite Material), MCM (Metal Composite Material) or HPL (High-Pressure Laminate) cladding. A “significant amount” will generally mean around 25% of the building’s façade. |
Where metal panels are present, the freeholder or managing agent should confirm in writing what material the external wall is made from. If the material cannot be established from the building records, a lender may request a specialist inspection.
Who pays for an EWS1?
The freeholder is responsible for paying for the fire risk assessment of their buildings and organising for an EWS1 form to be signed. However, they could pass a portion of these costs onto leaseholders, which can be thousands of pounds.
This is where buyers can get caught out! As an EWS1 is only valid for 5 years, it’s important your conveyancer explains to you exactly how these costs are outlined in the lease and whether they are passed onto leaseholders. If the EWS1 is due to be updated within the next year or two, you could be paying towards this as the new flat owner. If leaseholders are required to pay, the cost is usually included in the annual service charge.
Who arranges an EWS1 certificate?
The building owner or freeholder is responsible for arranging qualified fire engineers to carry out fire risk assessments and complete the EWS1 form. Leaseholders, valuers and lenders cannot arrange for an EWS1, only the legal owner of the building can do so. An EWS1 certificate is obtained after a qualified professional performs a fire-risk appraisal of the external wall system.
When purchasing a leasehold flat it is the seller or their conveyancer’s responsibility to request a copy of the EWS1 from the freeholder. It shouldn’t cost them anything to get a copy, but the speed at which it is received depends entirely on how organised and compliant the freeholder is.
Alternatively, you could try searching to see if the building already has an EWS1 on the Building Safety Information Portal.
Can I get a mortgage on a building affected by cladding?
Many major lenders will consider mortgages on affected buildings where there is an agreed remediation route, government or developer funding, or evidence that the leaseholder is protected under the Building Safety Act. As lender policies differ significantly, we recommend getting advice from a mortgage broker on which lenders would be suitable.
As a buyer, your purchase could be delayed if there is no clear timetable for remediation or written confirmation of who will pay. Some buyers have reported sales stalling, offers being renegotiated or lenders refusing to proceed because remediation dates or paperwork were unclear. Ideally, to ensure a smooth transaction the seller should aim to have as much of this information as possible ready from the start.
There is unsafe cladding on my building, what happens now?
A ‘B2’ rating means remedial work is required, but it does not automatically make a flat unsellable. The key questions are whether there is a funded remediation plan, who is responsible for the cost, whether the leaseholder is protected, when work will begin and whether the lender accepts the evidence.
Buyers should also consider disruption. Scaffolding, restricted balconies or windows, noise and lengthy works may affect day-to-day living even where the buyer is protected from the direct remediation cost.
Final thoughts
The UK Government Building Safety Programme estimates there are roughly 76,000 buildings over 18m and 42,000 buildings between 11-18m, which have enough cladding features to potentially trigger an EWS1 assessment. Approximately 37,800 of these are B rated buildings, which can limit your lending options for a mortgage. But, just to put things in perspective, there are an estimated 4.4 million residential flats in England, with only 600,000 - 700,000 requiring an EWS1 form. So, in the vast majority of cases this won’t be an issue.
However, regardless of whether a building needs an EWS1 form or not, lenders will often require confirmation of the material used for the external building walls. The key to property transactions going through smoothly, depends significantly on how prepared and honest the buyer and seller are about their circumstances from the start. If a seller or their legal advisor has all the necessary information relating to the building walls and fire risk assessments ready from the start, it enables buyers to make a more informed decision on whether the property is right for them.
