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FENSA Certificates Explained: Do You Need One to Sell Your House?
FENSA Certificates Explained: Do You Need One to Sell Your House?
📌 FENSA Explained: What You Need to Know
- What it is: FENSA is a government-authorised scheme that allows installers to self-certify that windows meet Building Regulations.
- The 50% Rule: Doors with less than 50% glass (e.g., many composite doors) do NOT require a FENSA certificate.
- New Builds: You generally do not need a FENSA certificate for new extensions or new build homes.
- The Protection: FENSA registered installers (like KJM) provide an Insurance Backed Guarantee (IBG) for peace of mind.
If you are replacing windows or doors in your home, you will hear the word “FENSA” a lot. But what actually is it? Is it just another logo, or is it a legal requirement?
At KJM Group, we believe in total transparency. We have been a FENSA Registered Company since the scheme began in 2002. Here is your complete guide to why that certificate matters—and exactly when you need one.
Table of Contents
1. FENSA & Competent Person Schemes
Since 2002, all replacement windows and doors must meet UK Building Regulations. To avoid every single homeowner having to pay the Council to inspect their new windows, the government created Competent Person Schemes (CPS).
FENSA is the most well-known of these schemes, but others like CERTASS and ASSURE perform the exact same legal function. They allow registered companies (like KJM) to “self-certify” their work.
2. Do I Need a Compliance Certificate?
Not every job requires one. The rules depend heavily on the type of work and the amount of glass.
The Compliance Checker
Action
Replacing frames and glass in existing openings.
Requirement
YES – MANDATORY
Example
Patio doors, French doors, Bi-folds.
Requirement
YES – MANDATORY
Example
Composite front doors or solid panel back doors.
Requirement
NO
⚠️ The 50% Glass Rule
Many homeowners panic when they can’t find a FENSA certificate for their front door. Don’t worry. If the door frame contains less than 50% glass (based on total area), it is exempt from FENSA registration. You do not need a certificate to sell your house in this case.
3. New Builds & Extensions
A very common question we get asked is: “I’ve just built an extension—where is my FENSA certificate?”
🏗️ The “Whole Build” Rule
You do NOT normally need a separate FENSA certificate for windows installed in new builds or new extensions.
Here is why:
- Local Authority Sign-Off: When you build an extension or a new house, the Local Authority Building Control (or an Approved Inspector) signs off the project as a whole. This inspection covers the foundations, the roof, the walls, and the glazing.
- The Proof You Need: Your overall Building Control Completion Certificate for the extension acts as your proof that the windows comply with regulations.
- Replacement Only: FENSA is a scheme primarily designed for the replacement of glazing in existing buildings.
4. Help! I’ve Lost My Certificate
This is the most common panic we hear from people selling their homes. If you have lost your paper certificate, don’t worry.
You can order a replacement directly from the FENSA website External (cost approx £25). If your installation was registered with CERTASS or another scheme, you will need to contact them directly.
5. Can I Do It Myself (DIY) or Use a General Builder?
Yes, but you cannot issue a FENSA certificate yourself.
If you (or a general builder who isn’t CPS registered) install the windows, you are legally required to apply to your Local Authority Building Control before you start work and pay for them to inspect the installation. This inspection fee often costs more than the money you save by doing it yourself!
📚 Related Guides
- Buying Guide: The Ultimate Guide to Replacement Windows
- Regulations: Part Q & Security Explained
- Pricing: Double Glazing Prices: How to Get a Fair Deal
6. Frequently Asked Questions
The certificate is valid for the life of the windows. It stays with the property, not the person. However, the Insurance Backed Guarantee (IBG) that typically accompanies it usually lasts for 10 years.
No. Conservatories are generally exempt from Building Regulations (provided they are separated from the house by external-quality doors), so they do not require a FENSA certificate. However, the doors connecting the house to the conservatory DO require one (if they are over 50% glass).
Yes. Never take a builder’s word for it. You can search for any company on the FENSA website to verify their registration number.
Mark Pearce is a highly experienced specialist in the double glazing industry, having built his knowledge from the ground up through hands-on experience in installation, manufacturing, sales, and business management. Beyond his role at KJM, Mark is a keen blogger, writer, and traveller, often sharing insights on the latest innovations in the home improvement industry.
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