EWS1 Forms Explained: What Every Flat Owner Needs to Know Before Selling
Selling a leasehold flat with cladding? Understanding your building's EWS1 rating could be the difference between a smooth sale and a failed transaction. In this guide, Hermens Property explains the different EWS1 ratings, how they affect buyers and mortgage lenders, and shares a recent real-life experience highlighting why sellers should check their building's status before going to market.ription.
Arman Khosravi
3/20/2026
If you own a leasehold flat in a modern apartment building, particularly one over 11 metres in height or with external cladding, one document has become increasingly important when selling your property: the EWS1 Form.
At Hermens Property we have recently experienced first-hand how an EWS1 issue can affect a sale. We agreed a sale of a fourth-floor penthouse to a cash buyer, only for the purchaser to make it clear that their offer was conditional upon the building having a satisfactory EWS1 rating. Understandably, they did not wish to incur legal costs until this had been confirmed.
It serves as a timely reminder that sellers should understand the EWS1 position before their property goes to market.
What is an EWS1 Form?
The External Wall System 1 (EWS1) Form was introduced following the Grenfell Tower tragedy to assist valuers and mortgage lenders in assessing whether the external wall system of a building presents an unacceptable fire risk.
It is not a legal requirement for every building, but where one exists it can have a significant impact on a property's marketability.
The form is prepared by a suitably qualified fire engineer or other competent professional and is intended to provide reassurance to lenders and purchasers.
Understanding the Ratings
The EWS1 Form will generally result in one of the following outcomes.
A1
No combustible materials are present within the external wall system.
This is generally regarded as the most straightforward outcome.
A2
Combustible materials may be present, but the level of risk is considered sufficiently low that no remedial works are required.
A3
Combustible materials are present but have been adequately mitigated through fire engineering measures.
B1
Combustible materials are present, however the assessor considers that no remedial works are required.
From a sales perspective, this is generally regarded as a satisfactory outcome and is accepted by most mainstream mortgage lenders.
B2
Combustible materials are present and remedial works are considered necessary.
This is where difficulties often arise. Whilst a B2 rating does not automatically make a property unsaleable, it can make mortgage lending considerably more challenging and often results in buyers seeking further reassurance regarding funding, remediation works and who will bear the cost.
Why Does This Matter?
Many sellers only discover there is an EWS1 issue after accepting an offer.
By that stage:
solicitors have been instructed;
legal costs have been incurred;
survey fees may have been paid; and
valuable time has been lost.
If the buyer's lender is unhappy with the building's EWS1 position, the transaction may stall or even collapse.
Even cash buyers are increasingly aware of these issues because today's purchase may need to be sold again in the future.
Our Recent Experience
We recently agreed the sale of a fourth-floor penthouse apartment.
The buyer was a first-time purchaser offering £415,000 in cash, placing them in an excellent position to proceed quickly.
However, from the outset they made one point absolutely clear:
Their offer was conditional upon the building having a satisfactory EWS1 rating.
They quite sensibly decided not to instruct solicitors until they had confirmation from the managing agents regarding the building's EWS1 status.
As estate agents, we immediately contacted the managing agents requesting:
confirmation of the current EWS1 rating;
a copy of the EWS1 Form; and
confirmation of any Building Safety Act documentation that might be required during the conveyancing process.
Obtaining this information at the earliest opportunity should help avoid unnecessary delay later in the transaction.
What Sellers Should Do Before Marketing
If your building has cladding, or you are unsure whether it does, we recommend obtaining as much information as possible before your property is advertised.
In particular, try to establish:
whether an EWS1 Form exists;
the current EWS1 rating;
whether any remediation works are planned or underway;
whether works have already been completed;
whether Building Safety Act documentation is likely to be required;
who manages the building; and
how long it takes the managing agents to produce the LPE1 management pack.
Having this information available at the outset gives confidence to buyers and enables their solicitors to progress matters more efficiently.
Building Safety Act 2022
Many higher-risk residential buildings are now also subject to the Building Safety Act 2022.
Depending upon the building and transaction, sellers may be asked to provide additional documentation, including leaseholder certificates or landlord certificates dealing with remediation liabilities.
These documents can take time to prepare and, in some cases, involve additional legal costs.
It is therefore sensible to identify these issues as early as possible rather than waiting until enquiries are raised by the buyer's solicitor.
The Bottom Line
The EWS1 Form has become an important part of many leasehold sales.
Understanding the building's position before marketing can:
reduce uncertainty;
improve buyer confidence;
minimise delays;
avoid unnecessary legal costs; and
reduce the risk of a sale falling through.
At Hermens Property, we believe good estate agency is about far more than arranging viewings. Identifying potential issues early, managing expectations and keeping transactions moving are all part of delivering a professional service.
If you are thinking of selling a leasehold apartment and would like practical advice on preparing your property for the market, we'd be delighted to help.
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