The average double glazing installation is around £7,000, and the Insurance Backed Guarantee premium on an installation that size averages around £22.97. Sometimes it’s a little less, sometimes it can be more — the things that affect your premium are listed below.
There’s one premium per installation — it’s not a yearly premium like your car or house insurance. You don’t pay as you go, either: you’re generally invoiced monthly for the installations you’ve registered, usually a month in arrears.
Guide premiums by trade
Here is a rough guide across the main trades — the average premium for a typical installation. Yours could be less or more; treat it as a starting point, not a quote.
| Trade | Average installation | Average premium (one-off, incl. tax) |
|---|---|---|
| Double glazing / roofline | around £7,000 | around £22.97 |
| Kitchen, bathroom or bedroom | around £8,000 | around £32.32 |
| General building | around £10,000 | around £32.32 |
| Roofing | around £8,000 | around £48 |
| Loft conversion | around £50,000 | around £265.92 |
| Solar PV (incl. battery) | around £10,000 | around £109.60 |
| Air-source heat pump | around £12,000 | around £300 |
Bigger builds like extensions (over £50,000) are worked out on the size of the installation — give us a ring for the number. For a closer look at your trade, see our cost guides for double glazing, roofing and renewables.
This is a HomePro average guide premium — not a quote. Every premium is worked out for the individual installer, so yours depends on the size of the installation, how long the guarantee runs, your track record as a business, the underwriter and how many installations you put through — so it can be lower or higher than the figure here. Premiums are the one-off total per installation and include Insurance Premium Tax. Correct as of August 2026 and subject to change. For the number on your own work, call 0800 131 0500.
What decides your premium
There are a number of factors at play when it comes to your premium, which is generally why you won’t see premiums listed on a website — they can be influenced by the following.
Your trade
Trades with a higher risk will generally pay more at the same installation value. For example, a renewable installation claim will likely be more expensive than a double glazing claim, so it costs more to cover.
The size of the installation
The bigger the installation, the more there is to cover, so the premium goes up. A conservatory costs more to cover than a single window, because the insurer is standing behind a bigger piece of work.
The guarantee period
With some trades there’s a choice of cover period, and a longer Insurance Backed Guarantee is a longer promise, so it costs a bit more. Double glazing and roofing Insurance Backed Guarantees tend to be for ten years. For double glazing specifically, the FENSA, CERTASS and Assure requirement is a minimum of six years, but with ten being standard you’re generally always above that. For renewables, the newly redeveloped MCS scheme requires at least six years.
Your own track record as a business
Your trading history, credit position and financial stability all feed in. A settled, established firm is cheaper to insure than a brand-new business.
The underwriter
The underwriter is the insurer that actually stands behind your guarantee, and different underwriters price differently. Some providers work with a single underwriter; others have several. That matters, because underwriters don’t all accept the same risks — some will only take on certain trades or certain types of business. A provider with more than one underwriter has more chance of placing you with one that will cover your work and price it fairly.
How many installations you put through
The more installations you process, the better the rate you can earn. And with no non-usage fee, a quiet month will not cost you anything. This is all dependent on the factors listed above, though — a high volume of work on its own won’t earn a discount if the risk or credit position doesn’t stack up.
Can your premium change after you’ve been quoted?
It can. It’s worked out from your circumstances, so if those change — your installation sizes, your business circumstances — the premium can be affected. Ask any provider what would change yours before you sign up.
What else to check before you compare providers
The premium on its own doesn’t tell you what you’ll actually pay. Check these three things before you compare providers.
Is there a non-usage fee?
Some providers charge you in the months you register nothing. A quiet spell then costs you money for no cover.
Is there a registration fee?
Some add a charge every time you register an installation, on top of the premium. Ask whether the number you’ve been given is the whole lot.
Is the tax included?
Insurance Premium Tax is either built into the figure you’re quoted or added on top. Check which, so you’re comparing like for like.
Membership and joining fees
Some providers charge a membership fee. It’s a separate cost from the guarantee premium — but where there is one, it usually more than pays for itself.
A good membership brings things a bare policy doesn’t: a dedicated account manager who knows your business and actually picks up the phone, ongoing vetting that keeps your accreditation in good standing, and your own public profile where the homeowners you’ve looked after leave reviews. That profile and rating can also win you work — which is a real return on any fee.
Some providers also charge a one-off joining or vetting fee when you first sign up. Whether a fee applies at all varies, so ask what’s included before you judge any provider on the premium alone. Our 10-point guide to choosing an Insurance Backed Guarantee provider walks through what to weigh up.
Can you pass the cost on to the homeowner?
Not as an itemised cost in your invoice — and this is important. Selling or advising on insurance is a regulated activity: only a business authorised as an insurance intermediary can do it, and as an installer you’re not one.
Which means if you itemise an Insurance Backed Guarantee on your invoice, charge for it separately, or advise your customer on the cover, you’re straying into regulated territory you’re not authorised for.
Instead, you simply need to build it into your price and show it as included. A line like “This quote comes inclusive of an Insurance Backed Guarantee from HomePro” does the job. We give you materials to hand over, and your account manager answers the homeowner’s questions if they have any.
How HomePro charges the premium
There’s one premium per Insurance Backed Guarantee, and you’re invoiced for the installations you’ve registered monthly, usually a month in arrears. There’s no non-usage fee, so a quiet month with nothing registered costs you nothing. There’s no charge to register an installation either, and the premium we quote already has Insurance Premium Tax in it — the figure you’re given is the figure you pay. The more you put through, the keener it gets.
For FENSA, CERTASS and Assure members, we can auto-issue your Insurance Backed Guarantees for you, so you’re not keying every installation in twice — and you stay in full control of what is and isn’t covered from your member portal.
One call sorts it. Ring 0800 131 0500 (Mon–Fri, 9am–5pm) or join here.
Frequently asked questions
How much does an Insurance Backed Guarantee cost a UK installer?
On average, around £22.97 for a typical double glazing installation, and more for bigger or higher-value trades. It’s a one-off per installation, and yours could be less or more depending on your trade, the size of the installation, how long the guarantee runs, your track record and the underwriter.
Is the premium fixed?
No. The figures here are averages. Yours is worked out for your installation and your business, so it can be lower or higher.
Is it a yearly cost?
No. Unlike car or house insurance, there’s a one-off premium for each installation, not a yearly bill. You’re invoiced monthly for the installations you’ve registered, usually a month in arrears.
Does my credit score affect it?
It can. Your trading history and financial standing are part of your track record, and a stronger one earns a keener premium.
Do I pay anything in months I register no installations?
Not with HomePro. Some providers charge a non-usage fee; we don’t — a quiet month costs you nothing.
Can I pass it on to my customer?
Not as a separate line. You build it into your price and show it as included — you can’t sell or advise on the insurance yourself.
Join UK installers who provide FCA-regulated Insurance Backed Guarantees with every installation through HomePro. Call 0800 131 0500 or join the HomePro network today.
Disclaimer: This post is for general information only. It is not financial, legal or insurance advice. While we take care to make sure the information is accurate, scheme rules, legal requirements and third-party details can change without notice — always check the latest position with the relevant scheme or official body before acting on anything here. HomePro accepts no liability for any loss arising from errors or omissions in, or reliance on, the information in this article. Insurance Backed Guarantees are subject to the terms, conditions and limitations of the individual policy.
