What is EWS1? A Guide for Leaseholders and RTMs
If you've been asked for an EWS1 by your mortgage lender, your managing agent, or a buyer's solicitor, you're not alone. It's one of the most common, and often most misunderstood, terms in UK building safety. In this post, we’ll break down what it actually means and how to secure one for your building.
What is an EWS1 form?
EWS1 stands for External Wall System 1. It's a standardised form that confirms whether a residential building's external walls (aka the cladding, insulation, balconies, and fire-stopping between floors) have been assessed and deemed safe by a qualified professional.
The form was introduced in 2019 as an industry-wide way to give mortgage lenders and valuers confidence in buildings with cladding, balconies, or other attachments on their external walls. It isn't a legal or fire safety certificate in itself; rather, it's a valuation tool, designed to answer a specific question: does this building's external wall present a risk that could affect its mortgageability?
Each EWS1 form is valid for five years from the date it's signed, provided nothing changes to the external wall system in the meantime.
Why EWS1 exists
The EWS1 process was developed in the years following the Grenfell Tower fire in June 2017, as lenders across the UK began asking for assurance that residential buildings with cladding didn't carry hidden fire risks. Before the EWS1 existed, there was no consistent way for a surveyor to check this, which left many buildings effectively unmortgageable and many leaseholders unable to sell or remortgage their homes.
What do the EWS1 ratings actually mean?
This is where most confusion sets in. An EWS1 form doesn't simply give a "pass" or "fail" verdict. Instead, it assigns one of five ratings, split into two categories, depending on what the assessment finds:
Option A: the primary wall materials are unlikely to support combustion:
A1 - No cladding or attachments present a fire risk. No remedial work required.
A2 - Cladding or attachments are present, but a risk assessment has confirmed no remedial work is needed.
A3 - The primary wall materials are fine, but attachments (typically balconies) may need remedial work.
Option B: combustible materials are present in the external wall system itself:
B1 - Combustible materials are present, but a qualified fire engineer has concluded the fire risk is low enough that no remedial work is required.
B2 - Combustible materials are present, and the fire risk is assessed as high enough to require remediation before the rating can improve.
In practice, A1, A2 and B1 ratings rarely cause problems for a sale, remortgage, or valuation. A3 and B2 are the two ratings that tend to stall transactions. Lenders are often unwilling to proceed until the necessary works are priced, funded, and underway (for a closer look at how each rating is assessed, our project partners at Anstey Horne have written a detailed breakdown of EWS1 categories).
Who actually needs an EWS1?
Not every residential building needs one. RICS guidance sets out a proportionate framework based on height, cladding type, and the presence of features like stacked balconies:
Buildings over six storeys with cladding, curtain wall glazing, or stacked balconies will generally need one.
Buildings of five or six storeys may need one where there's a significant amount of cladding, or where materials like aluminium composite material (ACM), metal composite material (MCM), or high-pressure laminate (HPL) panels are present.
Buildings of four storeys or fewer typically only need one if ACM, MCM, or HPL panels are present.
Buildings without any cladding at all, regardless of height, generally don't need one.
It's also worth knowing who can request one. An EWS1 assessment can only be commissioned by the party responsible for the building. That may be the freeholder, a residents' management company (RMC), or a right-to-manage company (RTM). It cannot be commissioned by an individual leaseholder acting alone. The process is usually arranged through a managing agent or director on the building's behalf.
How EWS1 relates to remediation
This is the part that catches most leaseholders and RTM directors out: an EWS1 form doesn't fix anything itself. It simply means that a qualified fire engineer has already looked at the building and concluded that remediation is needed before the rating can improve.
The EWS1 form itself is really just the outcome of a much more detailed technical survey, known as a Fire Risk Appraisal of External Walls, or FRAEW. This survey is carried out in line with the PAS 9980 methodology. The FRAEW is where the real technical assessment happens: intrusive inspection of the wall build-up, materials testing, and a full risk rating. The EWS1 form is simply the industry-recognised way of communicating that outcome to lenders and valuers.
What happens if your building needs remediation?
If your building has been assessed with a rating that requires remedial work, the encouraging news is that most leaseholders will not personally pay for cladding remediation.
For eligible buildings, funding routes like the Cladding Safety Scheme exist specifically to cover the cost of this work. Getting from "our building has a B2 rating" to "our building is fully remediated and safe" involves a fairly involved process of surveys, funding applications, contractor appointments and compliance sign-off. We've broken that full process down in our step-by-step guide to accessing government funding for cladding remediation.
How Archway FM can help
Archway FM manages the entire remediation journey on behalf of RTM companies, freeholders, leaseholders and managing agents. We manage everything from the first building assessment through to funding applications, contractor oversight, and the final, completed EWS1 certificate. If your building has an EWS1 rating that's causing problems with a sale or remortgage, or you're not sure where your building stands at all, we're happy to talk it through.
Frequently asked questions
Does every residential building need an EWS1? No. Whether a building needs one depends on its height, the type of cladding present, and specific features like stacked balconies. Many buildings, particularly those without cladding, don't need one at all.
How long does it take to secure an EWS1? This varies depending on the building's complexity and whether an intrusive FRAEW survey is required first. A straightforward visual assessment can be relatively quick; a full FRAEW-informed assessment for a more complex building takes considerably longer.
Does an EWS1 form expire? Yes. An EWS1 form is generally valid for five years from the date it's signed, provided there's no material change to the external wall system in that time. If remediation work is carried out, the form needs to be reissued to reflect the new rating.