Last reviewed: June 2026
TL;DR- Following the Grenfell Tower fire (2017), buildings above 11 metres with combustible cladding or external wall system issues face mortgage restrictions.
- The EWS1 (External Wall System) form was introduced to provide assurance to lenders and buyers about a building's cladding safety - though its requirement has been narrowed over time.
- The Building Safety Act 2022 introduced leaseholder protections limiting the costs that can be passed to leaseholders for cladding and fire safety remediation.
- Lenders have updated their criteria repeatedly since 2017 - the current position should be checked with a broker or specific lender before proceeding.
The Background: Grenfell and the Cladding Crisis
The Grenfell Tower fire of June 2017, which killed 72 people, prompted a national review of fire safety in residential high-rise buildings. The review identified that many buildings had external wall systems - including aluminium composite material (ACM) cladding of the type used at Grenfell - that did not meet fire safety standards. This triggered a widespread programme of building safety assessments across the UK's multi-storey residential building stock.
The mortgage market responded by restricting lending on affected buildings until safety was assured. For several years, many leaseholders in high-rise buildings found it impossible to sell, remortgage or obtain any mortgage on their flats due to unresolved cladding issues.
The EWS1 Form
The External Wall System (EWS1) form was developed by the Royal Institution of Chartered Surveyors (RICS), UK Finance and the Building Societies Association in 2019 to provide a standardised assessment of a building's external wall system. A qualified professional inspects the building and assigns it one of two outcomes: A (no combustible materials in the external wall system, no remediation needed) or B (combustible materials present, requiring further assessment or remediation). Different sub-categories determine what action, if any, is required before the building is deemed safe for mortgage purposes.
The requirement for EWS1 forms was subsequently narrowed. RICS guidance issued in 2021 reduced the scope of buildings requiring EWS1 to those above 18 metres in height or above 11 metres with specific risk factors. Many buildings below 18 metres that had been effectively unmortgageable due to EWS1 requirements were brought back into the market following this guidance change. Lenders updated their criteria accordingly, though practice varies between lenders.
The Building Safety Act 2022
The Building Safety Act 2022 introduced significant leaseholder protections. Leaseholders in buildings above 11 metres are protected from being charged for the cost of remediating historical building safety defects (including cladding) where the landlord or developer is responsible. Developers who built affected buildings are required to fund remediation. Government funding (the Building Safety Fund) is available for buildings where the responsible developer cannot be identified or has ceased trading.
These protections have improved the position of many leaseholders but the remediation process is slow and ongoing in many buildings. The mortgage market continues to evolve as remediation progresses.
Current Mortgage Market Position
As of 2026, the mortgage position for high-rise flats depends heavily on the specific building's status. Buildings that have completed cladding remediation and received appropriate sign-off are largely mortgageable again through mainstream lenders. Buildings where remediation is in progress or where the safety status is unclear remain restricted. A specialist broker and a solicitor experienced in building safety issues are important for any high-rise flat purchase or remortgage.
Frequently Asked Questions
Do I need an EWS1 form for my building?
Whether an EWS1 form is required depends on the building's height and the specific lender's criteria. RICS guidance indicates EWS1 is primarily relevant for buildings above 18 metres. Some lenders still request EWS1 for buildings above 11 metres with certain risk factors. The current lender criteria should be checked before assuming an EWS1 is or is not needed for a specific building.
Am I protected from cladding remediation costs as a leaseholder?
The Building Safety Act 2022 provides significant protections for leaseholders in buildings above 11 metres from being charged for historical cladding and building safety defect remediation where the developer or landlord is responsible. The specific protections depend on the nature of the defect, when it was built and other factors. The Building Safety Regulator and GOV.UK provide detailed guidance on leaseholder protections.
Can I sell a flat in a building that still has cladding issues?
Selling a flat in a building with unresolved cladding issues is difficult because most buyers will need a mortgage and mortgage availability is restricted for affected buildings. Some cash buyers purchase at a discount, accepting the unresolved risk. Disclosure obligations require the seller (and their solicitor) to disclose known building safety issues to any buyer. Selling without disclosure of known issues creates legal liability.
What is the Building Safety Fund?
The Building Safety Fund is a government fund to pay for the removal and replacement of dangerous non-ACM cladding on residential buildings above 18 metres in England where the developer cannot be identified, is insolvent or refuses to pay. Applications are managed by Homes England. Separate funding has been provided for ACM cladding remediation. The fund does not cover all types of building safety remediation - the scope is specific to eligible cladding types and building heights.
