Two window quotes for the same house can be thousands of pounds apart, and it’s rarely obvious why. One salesperson talks about “A++ rated glass” and a “today only” discount, another sends a one-page price with a few lines on it. How are you meant to compare them?
This guide walks you through comparing window quotes properly, line by line, so you know whether you’re paying a fair price for the windows you actually want. It also explains why the same windows can carry such different prices, and how to use that to your advantage.
Key points
- Most uPVC windows are built from a small number of profile systems, so the windows on two quotes are often almost identical.
- The big price differences usually come from sales costs and margin, not the product.
- Only compare quotes once they cover the same sizes, glass, hardware, fitting and certification.
- Watch out for “sign today” discounts, vague lines and large deposits.
Why window quotes vary so much
Most homeowners assume a more expensive quote means better windows. Often it doesn’t. Here’s how the supply chain usually works for uPVC windows in the UK:
- Profile system companies make the uPVC frame sections. There are only a handful of well-known systems used across the country.
- Fabricators buy those profiles, add glass units and hardware, and build finished windows to order.
- Installers buy finished windows from fabricators, then survey, fit and guarantee them.
Lots of installers in the same area buy from the same fabricators. So the windows on a quote from a national brand with a showroom and a sales team can be very close, sometimes identical, to the windows on a quote from a small local firm. What changes is everything on top: sales commission, advertising, showrooms and margin.
That’s good news. It means you can usually get the same windows for less, as long as you compare like for like.
What should be on a proper window quote?
A good quote tells you exactly what you’re buying. Before you compare prices, check each quote includes the following. If one is missing something, ask for it in writing.
1. A schedule of every window
Each window should be listed separately with its position (for example “front bedroom” or “W3”), its size, style and how it opens. Elevation drawings are even better, showing which panes open and which are fixed. Without this, you can’t tell whether two quotes are for the same thing.
2. The frame system and colour
Look for the profile system name and frame depth, and the colour inside and out. A white-both-sides window and a grey-outside, white-inside window are not the same price, and foiled colours cost more than white.
3. The glass specification
Check whether it’s double or triple glazed, and look for the energy rating or U-value. In England, replacement windows have to meet a maximum U-value of 1.4 W/m²K or a Window Energy Rating of band B or better, so any reputable quote will meet that. Higher ratings and triple glazing can be worth it, but make sure you’re comparing the same glass on each quote. Also check for toughened safety glass where it’s needed, obscure glass for bathrooms, and the type of spacer bar.
4. Handles, locks and extras
Handle colour, locking type, trickle vents, child restrictors and fire escape hinges on upstairs windows all affect price. Some quotes include them as standard, others list them as extras.
5. Fitting, removal and making good
Does the price include removing and disposing of your old windows, fitting, sealing, new cills and trims, and making good to plaster or render? These are where “cheap” quotes often get expensive later.
6. Certification and guarantee
Replacement windows must be signed off under building regulations. Most installers do this through a competent person scheme such as FENSA or CERTASS, and you should receive a certificate after fitting. Check the guarantee length and whether it’s insurance backed, so you’re covered if the company stops trading.
Red flags to look out for
- “Today only” discounts. A genuine price doesn’t disappear overnight. Big discounts for signing on the spot usually mean the starting price was inflated.
- A huge list price with a big discount. What matters is the final amount you pay, not the saving written next to it.
- Vague lines. Words like “allowance”, “sundries”, “TBC” or “to suit” can turn into extras later.
- Large deposits. Find out how much you pay before anything is made, and whether your deposit is protected.
- No mention of certification. If a quote doesn’t say who registers the work, ask.
We cover what to check on a conservatory quote in our guide to types of conservatory, and the same principles apply to doors. See our guides to composite door quotes, sliding patio doors and bifold doors.
How to compare window quotes like for like
Once you’ve checked each quote has the detail above, line them up side by side:
- Match the windows. Same number of windows, same sizes, same styles and openers.
- Match the spec. Same frame system (or equivalent), colour, glass, energy rating and hardware.
- Match the work. Same removal, fitting, making good and certification.
- Compare the final price, including VAT. Then compare guarantees, lead times and payment terms.
If quotes don’t match, you’re not really comparing prices. You’re comparing different jobs. This is the step most people skip, because it takes time and you need to know what you’re looking at.
How BeatMyWindowQuote saves you money
This is exactly what we do for you, for free. You upload the window quote you’ve already been given, and we:
- read every line and work out precisely what you’ve been quoted for, including the frame system, glass and hardware
- flag anything that looks off, like pressure discounts, vague lines or missing items
- ask vetted local installers to price the exact same windows, and go further up the chain to the fabricators who make them
- show you the prices side by side, cheapest first
Companies price the spec without knowing your name or your original price, so nobody can phone you or simply undercut by a few pounds. You only hear from the company you choose. It’s free for you because the company you choose pays us a fixed fee, and only once you’ve signed and your cancellation period has passed. You can read more about how that works on our about us page.
No quote yet? Use our online window designer to pick the style, colour and glass for each window, and we’ll get you 3 quotes for exactly what you designed.
Frequently asked questions
How many window quotes should I get?
Three is a good number, as long as they’re for the same spec. Three quotes for different windows tell you very little. That’s why we ask companies to price an identical schedule.
Is the cheapest window quote always the best?
Not if it’s cheaper because it leaves things out. Once quotes are like for like, cheaper genuinely means better value, so then it’s down to guarantee, reviews and lead time.
Do I need FENSA for replacement windows?
Your replacement windows must comply with building regulations. Using an installer registered with a competent person scheme, such as FENSA or CERTASS, is the usual way to do this, and you’ll get a certificate when the work is done. Keep it safe, as you’ll need it when you sell your home.
Can I negotiate a window quote?
Yes, but it’s much easier with a like-for-like comparison in your hand. Read more about our approach on the windows page or in our FAQ.
