EWS1 form outcomes explained, what A1 to B2 means for buyers

If you are buying a flat and the building has some form of cladding or external wall system, there is a decent chance your lender will ask for an EWS1 form before they will offer you a mortgage. EWS stands for External Wall System. The form was introduced in December 2019 by UK Finance and the Royal Institution of Chartered Surveyors after the Grenfell Tower fire exposed how little anyone really knew about what was stuck to the outside of residential blocks.

A qualified fire engineer or other suitably accredited professional inspects the external wall and signs off one of five outcomes. Those outcomes sit under two broad options. Option A covers buildings where the assessor decides no combustible materials are present in a significant quantity. Option B covers buildings where combustible materials are present and a further expert judgement is needed on whether they pose an unacceptable risk.

The form itself does not make a building safe or unsafe. It records a professional opinion at a point in time. That matters because the picture can change as remediation work is done, or as guidance evolves. Always check the date on any EWS1 you are shown and ask your solicitor whether it is still current.

Option A is broadly the good news territory. The assessor has looked at the external wall and concluded that the materials present are either non-combustible or present in such limited quantities that no further action is needed. But there are three grades within that, and they are not identical.

A1 means the assessor found no significant combustible materials at all. The cladding, insulation and any other external wall components are assessed as non-combustible. This is the cleanest possible outcome and lenders are generally comfortable lending against an A1 building without further question.

A2 means there are some combustible materials present, but the assessor has concluded they are limited in extent and do not require any remediation or further assessment. Again, most mainstream lenders will accept an A2 and proceed to offer. It is worth double checking with your specific lender because each one sets its own policy, but A2 is not a red flag.

A3 is where things get a little more nuanced. It means combustible materials are present to a limited extent, but the assessor has recommended some form of remediation or mitigation. The building is not deemed an unacceptable risk, but there is work to be done. Some lenders will accept A3, others will not. You need to ask your mortgage broker or lender directly, and you need to find out who is responsible for funding and carrying out that remediation before you exchange contracts.

Option B means the assessor found combustible materials in the external wall system and has gone on to make a judgement about the level of risk those materials pose. This is where things get more serious, and where the outcome really starts to affect your purchase.

B1 means combustible materials are present but, in the assessors professional opinion, they do not represent an unacceptable risk. No remediation is recommended. A number of lenders will accept B1, though the pool is smaller than for A1 or A2. Your broker needs to check this with your specific lender early in the process, not after you have paid for a survey.

B2 is the outcome that stops transactions in their tracks. It means combustible materials are present and the assessor has concluded they do present an unacceptable risk. Remediation is required. The vast majority of mainstream lenders will not lend on a B2 building until the remediation has been completed and a new EWS1 with a better outcome has been issued. Some lenders will not touch it at all, even post-remediation, without a fresh full assessment.

A B2 does not automatically mean you should walk away, but you need to go in with your eyes open. The key questions are who is paying for the remediation, when it will happen, and what the building is worth in its current state.

Under the Building Safety Act 2022, leaseholders in qualifying buildings are protected from being charged for cladding remediation costs in many circumstances. Whether your building and your lease qualify is a legal question that your solicitor must answer for you. Do not assume you are protected without getting that confirmed in writing.

On price, a B2 building is effectively unmortgageable for most buyers right now. That limits your buyer pool to cash purchasers, which puts real downward pressure on value. If you are a cash buyer considering a B2 flat at a reduced price, you are essentially betting on the remediation happening, being funded by someone other than you, and producing a better EWS1 outcome in a reasonable timeframe. That is a significant gamble. Some buyers have waited years. Others have seen buildings progress through remediation relatively quickly. There is no universal answer.

If you are not a cash buyer, a B2 outcome means you almost certainly cannot proceed unless and until the remediation is complete and a new EWS1 is issued. Your solicitor should flag this clearly. If they do not, ask them directly.

Lender policies on EWS1 are not uniform and they do change, so treat any general guidance here as a starting point rather than gospel. That said, the broad picture as of late 2026 is fairly consistent across mainstream lenders.

A1 and A2 are accepted by the overwhelming majority of lenders with no additional conditions. A3 is accepted by some lenders but not others, and the remediation plan matters. B1 is accepted by a meaningful number of lenders but the list is shorter, and your broker needs to check. B2 is not accepted by most mainstream lenders for mortgage purposes until remediation is complete and a better outcome has been certified.

If your building does not need an EWS1 at all, because it falls outside the criteria that trigger the requirement, your lender should not be asking for one. The criteria have been updated since 2019 and not every building with cladding requires a form. If a lender is insisting on one for a building that does not meet the threshold, that is worth pushing back on with your broker.

Always confirm your specific lenders position in writing before you commit to any costs. Broker advice here is genuinely valuable because a good one will know which lenders are currently accepting which outcomes.

First, find out whether the building already has an EWS1 in place. Ask the seller, the managing agent or the freeholder. If one exists, get a copy and check the outcome and the date. An EWS1 that is several years old may not reflect work that has been done since, or may have been superseded by updated guidance.

Second, tell your mortgage broker the EWS1 outcome before you apply. They can check which lenders will accept it and save you from a wasted application and a wasted valuation fee.

Third, instruct a solicitor who has experience with leasehold flats and building safety issues. This is not the moment to use whoever is cheapest. Your solicitor needs to check the lease, the service charge history, any building safety fund applications, and whether the building is enrolled in a remediation scheme.

Fourth, if the outcome is B2 or A3, find out exactly what the remediation plan is, who is funding it, and what the realistic timeline looks like. Get this in writing if you can. Your solicitor can raise enquiries with the freeholder or managing agent.

Finally, do not let enthusiasm for a flat override the numbers. A building with unresolved fire safety issues is a harder sell when you come to move on, and the costs and delays involved in remediation can be significant even when you are not being asked to fund them directly.

Building safety law and lender policy in this area have both moved considerably since 2019 and they are still evolving. The Building Safety Act 2022 introduced significant protections for leaseholders but the detail of who qualifies and in what circumstances is genuinely complex. The government has also updated guidance on which buildings require an EWS1 assessment more than once.

Anything in this article that touches on legal protection, lender policy or government schemes may have changed since it was written. Please confirm the current position with your solicitor before making any decisions. A good solicitor will know the current state of play and will flag anything that has shifted recently. This piece gives you the vocabulary and the framework, but it is not a substitute for professional advice on your specific building and your specific lease.