EWS1 Certificates: What London Flat Owners Need to Know

Background and context

Following the Grenfell Tower tragedy in 2017, mortgage lenders became increasingly concerned about the fire safety of external wall systems — particularly those incorporating combustible cladding materials. The EWS1 form was developed by the Royal Institution of Chartered Surveyors (RICS), UK Finance, the Building Societies Association and other industry bodies to provide a standardised way for a qualified professional to confirm whether the external wall system of a building poses a fire risk.

For flat owners in London, the practical impact has been significant. Buildings that cannot produce an EWS1 certificate with a satisfactory rating may find that mortgage lenders will not lend against individual flats, effectively preventing sales and remortgages. This has affected thousands of leaseholders across London boroughs including Tower Hamlets, Greenwich, Newham and Southwark, where post-2000 residential developments with various cladding systems are concentrated.

When an EWS1 certificate is required

Not all buildings require an EWS1 certificate. The requirement is driven primarily by mortgage lender policy and is applied on a risk-based approach. Buildings most likely to require an EWS1 form include residential blocks over 18 metres (typically six storeys or more) with any form of cladding, buildings between 11 and 18 metres where the external wall system incorporates combustible materials, and any building where a lender has specific concerns about the external wall construction.

Buildings below 11 metres with no cladding concerns are generally exempt from the EWS1 requirement, following updated lender guidance issued in 2023. However, lender policies vary, and some may still request assessment in specific circumstances.

The assessment process

An EWS1 assessment must be carried out by a suitably qualified professional — typically a chartered building surveyor or fire engineer who holds the relevant competency qualifications. The assessor inspects the external wall system, reviews available construction records and design information, and determines the appropriate rating for the building.

The assessment involves a visual inspection of the external walls, review of any available design and construction documentation, identification of the materials used in the external wall build-up, assessment of balconies, spandrel panels and other components, and a determination of whether any combustible materials are present and whether they present a fire risk in context.

Understanding the implications

A B2 outcome means combustible materials are present and the assessor considers the fire risk sufficiently high that remedial works are required. It does not, by itself, determine immediate danger, urgency, interim measures or occupation. Those decisions require the underlying fire-risk evidence and the responsible dutyholders' assessment; a lender or valuer separately decides the transactional effect. For buildings in England at least 11 metres high, lenders may consider mortgage applications before remediation is complete where there is evidence of a recognised government remediation scheme, developer remediation or applicable leaseholder protections. Individual lender policies and regulatory requirements still apply. See the UK Finance industry statement on cladding.

However, a B2 rating does not necessarily mean the building is imminently dangerous. Fire risk assessments, waking watches or alarm systems may be in place as interim measures. The B2 rating is a trigger for remediation, not an indication that the building must be evacuated.

Engaging with the freeholder and managing agent

The freeholder or responsible entity is typically responsible for commissioning and managing the remediation works. As a leaseholder, you should request a clear remediation timeline, details of the proposed scope of works, an explanation of how costs will be allocated and information about any funding applications that have been made or are planned. Transparent communication from the freeholder is essential.

Funding routes: CSS and BSF

Since 1 September 2025, new applications for government cladding remediation funding for eligible buildings over 11 metres in England, including London, go through the Cladding Safety Scheme (CSS), administered by Homes England. This includes eligible buildings between 11 and 18 metres; height alone does not establish eligibility. The responsible entity or its authorised representative applies, with the scheme-specific building, legal and technical evidence. Check the current CSS guidance and the CSS/BSF transition guidance for the route that applies to an existing application. A separate targeted route is available for eligible buildings under 11 metres; see the current under-11m funding criteria and application window.

Navigating the application process for these schemes requires careful preparation of technical documentation, cost estimates and evidence of building ownership and management arrangements. Our CSS / BSF Funding Advisory service supports freeholders and managing agents through this process.

The role of FRAEW and PAS 9980

In many cases, a more detailed assessment under PAS 9980:2026 (Fire Risk Appraisal of External Walls) may be appropriate. This provides a proportionate, risk-based assessment that considers the specific context of the building, rather than applying a blanket pass/fail approach. A FRAEW assessment may determine that the risk is lower than initially indicated and that a less extensive remediation scope is appropriate, potentially saving significant cost and time.