Most people meet the word FENSA twice. The first time is when their windows go in, and it barely registers. The second is years later, when a buyer's solicitor asks for a certificate nobody can find, usually a fortnight before exchange. We take calls about that second moment all the time, so let's untangle it properly. What the certificate is, why it matters, and every way out when it's gone missing.
What a FENSA certificate actually is
Since 2002, replacement windows and doors in England and Wales have had to comply with building regulations. Thermal performance, safety glazing, ventilation, escape openings, the lot. Compliance needs proof, and there are two ways to get it. You can pay your council's building control to inspect and sign off each job, or you can use an installer registered with a competent-person scheme, who self-certifies the work and notifies the council for you. FENSA, the Fenestration Self-Assessment scheme, is the biggest of these schemes. Certass is another. The certificate that lands a few weeks after installation is your legal evidence that the work met the regulations. What it isn't is a quality mark or a guarantee. It's a compliance document, and the installer's guarantee is a separate thing. You want both.
Why the certificate turns up when you sell
The standard conveyancing enquiry pack asks whether windows have been replaced since 2002 and requests the certificates. Solicitors ask because unproven work becomes their client's problem the day contracts complete. A missing certificate rarely kills a sale, in our experience, but it reliably slows one down, and it hands the buyer a bargaining chip at the worst possible moment. Together with the guarantees and the energy-rating paperwork, it forms the small stack of documents that turns new windows into an asset at sale rather than an awkward question.
Lost it? Start with the cheapest fix
- Reissue: FENSA keeps records. Order a replacement certificate from their website for a small fee, and Certass offers the same. All you need is the installation address and a rough date. Most post-2002 jobs by registered installers turn up in minutes.
- Ask the installer: if the company is still trading, they'll hold records too and can confirm the registration for you.
- Retrospective building control: for work that was never certified, councils offer regularisation. An inspection and a fee, with the risk they ask for corrections. Trickle vents and safety glass are the usual gaps.
- Indemnity insurance: the pragmatic conveyancing fix. A one-off premium, typically £50-£200, insures the buyer against enforcement. It gets the sale through, but it proves nothing about the windows, and it's void if you contact the council first. Take advice before doing anything in the wrong order.
What this means when you're buying windows
One question costs nothing and sorts the market instantly. Who certifies this work, and when do I get the certificate? A registered installer answers without blinking, and the certificate arrives automatically a few weeks after completion. File it with your deeds next to the guarantee and forget about it. Vague answers mean one of two things. Either the installer isn't registered, and your money will end up funding a building-control application or a future indemnity policy, or the company is hoping you won't notice. It's one of the five questions that separate good suppliers from the rest, and every Prime Fabrication Windows, Doors & Glazing installation is certified as standard, with the paperwork issued without any chasing.
Where FENSA does and doesn't apply
- FENSA covers replacement windows and doors in homes. It doesn't cover new-build (that's building control), extensions and conservatories (usually building control too), commercial premises, or repairs and glass-only replacement, which need no certification at all
- A FENSA certificate isn't a guarantee. The installer's separate guarantee covers defects, while FENSA certifies regulatory compliance and requires the installer to offer insurance-backed protection for deposits and guarantees
- Certass and the other competent-person schemes are equally valid. Solicitors accept any of them; FENSA has simply become the generic word, the way Hoover did
- The certificate belongs to the property, not to you. Leave it, or a copy, for the next owner as part of the house's paper trail
A quick FENSA audit of your own house
Do this before a sale forces you to. List which windows and doors have been replaced since 2002, dig the certificates out of your deeds pack, and order reissues now for any gaps. A small fee today beats a conveyancing scramble later. Pre-2002 work needs nothing. If you've inherited mystery windows with no paper trail at all, price the indemnity route in advance so it becomes a line item rather than a crisis. Ten minutes of filing is genuinely the whole job.
Landlords should multiply that advice across the portfolio. Tenanted properties collect replacement work through successive ownerships, and the gaps surface at refinancing just as surely as at sale. One afternoon reconciling each property's windows against its certificates, ordering reissues where the work was registered and pricing regularisation or indemnity where it wasn't, turns an unknown liability into a filed folder. Your conveyancer, your lender and your eventual buyer will all ask the same question. Having the answer ready costs almost nothing, and it pays every single time.
Frequently asked questions
What is a FENSA certificate?
It's proof that replacement windows or doors complied with building regulations, issued when a FENSA-registered installer self-certifies the work and notifies your council. It's a compliance document, separate from and additional to the installer's guarantee.
How do I get a copy of a lost FENSA certificate?
Order a reissue straight from FENSA's website using the property address. There's a small fee and it takes a few days. Certass does the same for its certificates, and most registered installations since 2002 are traceable even decades on.
Can I sell my house without a FENSA certificate?
You can, but expect the buyer's solicitor to raise it. The usual fixes are a reissued certificate if the work was registered, retrospective building-control approval, or indemnity insurance at £50-£200, which protects against enforcement rather than proving the windows comply.
Do window repairs or new glass need FENSA?
No. Repairs, new hardware and glass-only replacement into existing frames sit outside the requirement. Full frame replacement is what triggers certification, which is one reason glass-only upgrades involve so little paperwork.
Is FENSA a guarantee of quality?
No. It certifies compliance with the regulations, not workmanship or product quality. Judge quality on specification, track record and the written guarantee. FENSA registration does oblige installers to offer insurance-backed guarantee protection, which is well worth confirming.
What happens if windows were fitted without certification?
The house isn't illegal to live in, and enforcement against old work is rare, but the gap will surface when you sell. Regularise through building control, who may ask for corrections such as trickle vents, or bridge it with indemnity insurance. Don't alert the council before deciding, because that can close off the indemnity route.
Certified as standard, filed for you
Every installation we do is registered and certified, and the certificate arrives alongside your 10-year insurance-backed guarantee without you lifting a finger. Dull paperwork now, a far smoother house sale a decade from now.
Call 07533 830717, WhatsApp us a photo for a fast quote, or request a free quote online.