Advice for

Meet your
FENSA Advisor

This is Harry.

You might recognise him from our TV ad.

Harry works for a FENSA Approved installation company. He's on a mission to help professionalise installers and protect homeowners across the UK, so he started this advice column

Harry's advice

Why it’s good to shop around for installers

By getting at least three quotes (the more the better) you’ll be able to compare the estimates given by different companies and see if you’re being quoted like for like.

Remember that the cheapest quote is not necessarily the best one - a good installer is always in demand. Also, always ask for references and be sure to follow these up.

Why insurance to back the installer’s guarantee is a key protection

Is there adequate insurance cover and is the installer’s work guaranteed? Any reputable company offers its own guarantee.

However it is now a legal obligation that all domestic glazing installers registered with a scheme like FENSA provide insurance backing of the guarantee.

This covers your installation should the company cease to trade within the life of the guarantee up to ten years.

Why it’s good to seek a referral from family or friends

Word of mouth is a great way to find out about contractors when you need someone to replace your windows or doors.

Ask family, friends, neighbours and colleagues if they can recommend an installer. After all, a recommendation means more when it comes from someone you know and trust.

Why it’s important to get everything in writing

Any estimates and timeframes should be agreed upon in writing. Insist on written contracts and make sure to agree on a completion date.

This can avoid confusion further down the line.

What to check before
appointing an installer

Before you appoint an installer to replace your windows and doors, ask them:

“Will I get a FENSA certificate when the job’s done?”

Why? Because by asking that one, simple question you’ll discover immediately whether the company you’re considering using is right for you.

If they say no, you should say no.

Why? Because a FENSA certificate provides proof that your installer’s work complies with Building Regs, uses energy efficient products, and is registered with the local council (a legal requirement).

Only a FENSA Approved Installer can get you the FENSA certificate.

Also, it means their warranty is insured. Good to know, in case anything goes wrong. There are many unprofessional installers out there, so you need to be careful.

Why you should always ask for a FENSA certificate

Your FENSA certificate isn’t just a nice-to-have, it’s a need-to-have. Because the certification means you’re working with a professional who’ll meet two legal requirements and provide you with an important level of protection.


Most people haven’t the time, knowledge or inclination to check these three things themselves. So, what are they?


Your FENSA certificate is your assurance that the installer who fits your windows or doors will comply with Building Regulations and means that your installation(s) will be registered with the Local Council. These are legal requirements and proof of them is essential when selling your home.

In addition, your FENSA certificate is proof that your installer’s warranty is insured. Reassuring to know if anything goes wrong, and their business gets into trouble.

So remember: you’re not just asking for a FENSA certificate. You’re asking if that window or door installer you’re considering to use is professional, will comply with Building Regs, register your installation, and offer an insured warranty.

That’s why we say the FENSA certificate is all the proof you need of a job done right.

Why you should always use a FENSA Approved Installer

There are many good installers out there who’ll do a good job of fitting your replacement windows and doors. The crucial question is, “Are they good enough?”


How can you be sure? Ask a friend for a recommendation? Check a Google review? Or just look at their past work? There’s only one way to be certain: find out if they’re a FENSA Approved Installer.


Because to become a FENSA Approved Installer, that company must pass a stringent vetting process. And then pass regular assessments to prove consistency with the relevant Building Regulations standards.

By using a FENSA Approved installer, you’re protected from the risk of cowboys who don’t adhere to these standards. Poor or, worse, illegal work could cost you hundreds to put right. And even if your non-approved installer’s work is okay, it must be registered with the local authority. If that isn’t done it will cost you time and a surprising amount of money arranging assessment by Building Control.

So, when it comes to replacing doors and windows remember that a FENSA Approved Installer will save you time, money, and worry. And you’ll gain the peace of mind that comes from knowing the job’s done right. Which is also valuable to prove when selling your home.

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