FENSA is a government-authorised scheme that lets registered installers self-certify that replacement windows and doors comply with UK Building Regulations. If you’ve had replacement glazing fitted in England or Wales since April 2002, you need either a FENSA certificate or a Building Regulations Compliance Certificate from your local authority without one, selling your home can be delayed.

What Is FENSA?

FENSA stands for the Fenestration Self-Assessment Scheme. It’s a government-authorised Competent Person Scheme that covers replacement windows, doors, roof windows and roof lights in England and Wales.

The scheme was set up by the Glass and Glazing Federation, and its job is straightforward: it lets registered installers confirm their own work meets Building Regulations, instead of your local council sending an inspector round every time.

A FENSA certificate is the paperwork that comes out the other end. It shows:

  • The installation meets the required thermal performance standards
  • The work complies with Building Regulations
  • The installer was a competent, FENSA-approved person or company at the time

Why Was FENSA Introduced?

Since April 2002, replacement glazing in England and Wales has fallen under Building Regulations. Anyone installing replacement windows or doors has to meet updated thermal performance standards the aim being to cut energy loss from the much larger stock of existing homes, not just new builds.

Before FENSA, every replacement window job would have needed a visit from local authority Building Control. FENSA gave homeowners and installers a faster, self-certifying alternative which is also why it was the first scheme of its kind in the UK.

Quick takeaway: FENSA exists because Building Regulations changed in 2002, and someone needed to check compliance without clogging up every council’s Building Control department.

What Does a FENSA Certificate Actually Cover?

FENSA certificates cover the replacement of external windows, doors, roof windows and roof lights in a home on its original footprint, with no change to room use or size.

FENSA does not cover:

  • New build homes
  • Extensions
  • Conservatories and orangeries
  • Commercial premises
  • Repairs where the frame isn’t replaced

If your project falls into one of those categories, FENSA isn’t the right route — you’d need Building Control approval instead.

How Is a FENSA Certificate Different From Building Control Approval?

There are two legitimate ways to prove replacement glazing complies with Building Regulations:

  1. A FENSA certificate issued because the installer was FENSA registered and self-certified the work
  2. A Building Regulations Compliance Certificate issued by your local authority’s Building Control department after a final inspection

Both prove the same thing. The difference is who does the checking a FENSA-registered installer, or the council directly.

If you use an installer who isn’t FENSA registered (or registered with another competent person scheme), it becomes your responsibility to arrange Building Control sign-off yourself.

Do You Actually Need a FENSA Certificate?

Yes if replacement windows, doors, or roof lights were fitted in your home after April 2002, you need proof of compliance in one of the two forms above.

This matters most when you come to sell:

  • Conveyancing solicitors and buyers’ surveyors will ask for it
  • Missing certificates are one of the more common causes of delay in a house sale
  • Some buyers’ mortgage lenders may also want to see it before completion

A FENSA certificate stays with the property, not the person who had the work done so if you’re buying a home with older replacement windows, it’s worth asking the seller for theirs.

What Happens If You Don’t Have One?

If you can’t locate a FENSA certificate or Building Control certificate for past glazing work, you have two options:

  • Order a replacement if the original installer was FENSA registered, a replacement certificate can be requested through FENSA directly, typically for a small fee (around £25)
  • Arrange a retrospective inspection if the installer wasn’t registered with FENSA or another competent person scheme, you’ll need to contact your local authority’s Building Control department and pay for an inspection

Skipping this step isn’t just a paperwork issue. Non-compliant glazing discovered later can mean remedial work, extra cost, or delays right when you’re trying to sell.

How Do I Check If My Installer Is FENSA Registered?

Before any replacement window or door job goes ahead, it’s worth checking your installer’s FENSA status directly using FENSA’s own “Find an Installer” search on fensa.org.uk. It only takes a minute, and it means you’re not relying on a badge on a van or a claim in a quote.

Ask your installer to confirm, in writing:

  • Their FENSA registration number
  • Whether the certificate will be registered with the local council automatically
  • How long after completion you should expect to receive it (usually a couple of weeks)

What If I’ve Lost My FENSA Certificate?

If your windows or doors were fitted by a FENSA-registered installer but you’ve since lost the paperwork, a replacement can be ordered through FENSA’s website for a small administration fee. It’s far cheaper and faster than arranging a fresh Building Control inspection.

Is Secure Trade Frames FENSA Registered?

Yes. Secure Trade Frames is FENSA registered and BFRC certified, so every replacement window and door installation we carry out is self-certified compliant with UK Building Regulations, and registered with your local council on your behalf.

That means:

  • You’re not left chasing paperwork after the job’s done
  • Your installation is backed by our insurance-backed guarantee
  • You’ll have everything you need if you ever come to sell

You can see our full accreditations here, and read more about our 10-year guarantee on every installation.

What Should You Remember About FENSA?

  • FENSA is a government-authorised scheme letting installers self-certify Building Regulations compliance
  • It’s covered replacement windows, doors, roof windows and roof lights in England and Wales since April 2002
  • It doesn’t cover new builds, extensions, conservatories, or commercial premises
  • You need either a FENSA certificate or a Building Control certificate for any replacement glazing done since 2002
  • Missing certificates are a common cause of delay when selling a home
  • Secure Trade Frames is FENSA registered, so every job comes with proper paperwork as standard

Your home deserves more than just four walls; it deserves windows and doors built to last, crafted to perform, and installed by people who genuinely care. Secure Trade Frames brings Leicester’s finest A-rated uPVC windows, composite doors, and conservatories straight from their own factory floor to your doorstep, with the craftsmanship and personal service to match. Don’t settle for draughts, noise, or soaring energy bills any longer. Take the first step toward a warmer, safer, smarter home. Call 0116 261 1155. Find them at 7A Earls Way, Churchill Industrial Estate, Thurmaston, Leicester, LE4 8DL.