Buying and Selling High-Rise Flats: Cladding, EWS1 and the Building Safety Act

Since the Grenfell Tower fire, buying and selling flats in tall buildings has become one of the most demanding areas of residential conveyancing. Cladding concerns, external wall surveys and the Building Safety Act 2022 have added real complexity — and many firms now avoid these transactions altogether. We don't. Here's what you need to understand.

The EWS1 Form

The External Wall System (EWS1) form records a fire-safety assessment of a building's external walls. It is not a legal requirement — it exists because mortgage lenders and valuers ask for it.

• Buildings over 18m (roughly 7+ storeys): an EWS1 is almost always required where there is cladding, rendered walls or combustible balconies.
• Buildings 11–18m: required only where specific risk factors are present.
• Buildings under 11m: generally not required unless high-risk materials are involved.

An EWS1 is valid for five years. Importantly, only the freeholder or building manager can commission one — an individual leaseholder cannot. The outcome ratings matter: A1/A2 broadly mean no remediation needed, while B1/B2 indicate work is required. Its absence can stop a mortgage — and therefore a sale — in its tracks, which is why we raise it at the very start.

The Building Safety Act 2022: Leaseholder Protections

This is the part that reassures most buyers. For flats in a "relevant building" (broadly 11m or five storeys and above), the Act shifts the cost of fixing unsafe cladding away from leaseholders.

• Cladding remediation: a qualifying leaseholder pays nothing towards removing unsafe cladding.
• Non-cladding defects: contributions are capped (broadly £10,000 outside London, £15,000 in London) and spread over ten years — with many leaseholders exempt entirely.
• Wealthy or responsible landlords: where the landlord meets the contribution condition, or is the developer responsible for the defect, leaseholders are further protected.

What Makes a "Qualifying Lease"

The protections depend on holding a qualifying lease. Broadly, that means a long lease (over 21 years) where, on 14 February 2022, the flat was your main home or you owned no more than three UK properties. Status is confirmed through a Leaseholder Deed of Certificate, and getting this right is essential — it's what unlocks the cost protection and, increasingly, what lenders want to see.

Higher-Risk Buildings

Buildings over 18m are "higher-risk buildings" under the Act. They come with additional duties on the Accountable Person, including registration with the Building Safety Regulator and maintaining fire-safety information. As a buyer, you'll want comfort that these obligations are being met.

A Practical Checklist

• Ask the freeholder or managing agent for the current EWS1 and check the rating.
• Confirm your qualifying lease status and complete a Leaseholder Deed of Certificate.
• Check whether the building is in a government remediation scheme (such as the Building Safety Fund) if works are outstanding.
• Confirm your lender's specific policy — requirements still vary between lenders.

How Bonsai Law Can Help

High-rise and higher-risk buildings carry paperwork that can derail a sale if it isn't handled early and properly. We act on these purchases and sales, chase down the EWS1 and building-safety information, and make sure your qualifying-lease protections are secured before you're committed. If you're buying or selling a flat in a tall building, get in touch — we'll tell you straight where things stand.