FENSA Certificates: What UK Homeowners Need to Know

FENSA certificates are among the most frequently requested documents in UK residential property transactions — and among the most commonly lost. If you have had windows or doors replaced since April 2002 and cannot produce FENSA certificates or equivalent documentation, you may face delays in your property sale and potentially costly retrospective building control approval. This guide explains exactly what FENSA is, why certificates matter, and what to do if yours are missing.

What Is FENSA?

FENSA — the Fenestration Self-Assessment Scheme — is a government-authorised competent person scheme for the installation of replacement windows and doors in dwellings in England and Wales. It was established in April 2002 when the replacement of windows and doors became notifiable work under Part L of the Building Regulations, requiring compliance with energy efficiency standards.

FENSA-registered installers can self-certify that their installations comply with Building Regulations without the need for a separate local authority building control application. When an installation is complete, the installer registers it with FENSA and the homeowner receives a FENSA certificate confirming compliance.

Why FENSA Certificates Matter When Selling

When a property is sold, the buyer's solicitor will ask — through the standard Law Society TA6 form — whether any windows or doors have been replaced since April 2002 and whether Building Regulations approval was obtained. A FENSA certificate is the standard evidence of compliance. Without it, a seller must either obtain retrospective building control approval or arrange indemnity insurance.

Retrospective approval involves local authority building control inspecting the installation. For installations that are years or decades old, this may be difficult and potentially expensive if any element does not meet current standards. Indemnity insurance is more commonly used but adds cost and may not satisfy some buyers' solicitors.

What a FENSA Certificate Contains

A FENSA certificate records the property address, the date of installation, a description of the work carried out — typically the number and type of windows or doors installed — the name and FENSA registration number of the installer, and a unique certificate reference number. The certificate confirms that the installation was registered with FENSA and complies with the relevant Building Regulations.

How to Check if Your Windows Have a FENSA Certificate

If you have lost your FENSA certificate or have bought a property and are unsure whether replacements were certified, you can check the FENSA database at fensa.org.uk. Search by property address to find any registered installations. The database goes back to 2002 and is publicly accessible.

Where an installation is found in the database, a duplicate certificate can be ordered for a small fee. Where no registration is found for work that you know was carried out, the installation may have been done by a non-FENSA installer — in which case it should have been approved by building control directly, and you should check whether a building control completion certificate was issued.

Alternative Certification Schemes

FENSA is not the only competent person scheme for window and door installations. CERTASS is another government-authorised scheme operating on the same basis. Certificates from CERTASS-registered installers are equivalent to FENSA certificates for the purposes of Building Regulations compliance and property transactions.

Key Takeaways

• FENSA certificates confirm that replacement windows and doors comply with Building Regulations — required for all replacements in dwellings since April 2002.
• Solicitors routinely request FENSA certificates in property transactions — missing certificates require retrospective approval or indemnity insurance.
• Certificates can be checked and duplicates ordered via the FENSA database at fensa.org.uk.
• CERTASS certificates are equivalent to FENSA certificates and equally acceptable.
• Where no FENSA or CERTASS registration exists, a local authority building control completion certificate may have been issued — check with your local council.
• Keep FENSA certificates for the lifetime of the windows and transfer them to buyers on sale.