How to compare window quotes

Getting three quotes is easy. Comparing them properly is where homeowners either save money or get caught out. Two quotes for “the same” windows can differ by hundreds of pounds simply because the specification, the fitting or the guarantee is not the same. This checklist shows how to compare window quotes line by line so you are judging genuine like-for-like value, not headline figures.

Homeowner comparing window quotes at a kitchen table — Lay quotes side by side and check they cover the same specification.

1. Check the specification matches

Before you compare price, make sure every quote is for the same thing: the same frame material, the same window style, the same glazing (double or triple, glass type and energy rating) and the same colour or finish. A cheaper quote often turns out to be for a lower spec. Our guides to window prices by material and window prices by type help you pin the spec down.

2. Confirm what fitting includes

A quote should be for supply and fit. Check it covers removing the old windows, disposing of them, making good the surrounding brick or plaster, and any scaffolding for upper floors. If one quote excludes making-good and another includes it, the cheaper headline may cost more once the job is done.

3. Compare the guarantee

Look at what happens after installation. A good quote includes a written workmanship guarantee, an insurance-backed guarantee (so cover survives if the firm ceases trading) and deposit protection. These are as important as the price — they are what stands behind the work.

4. Check accreditations

Replacement windows must comply with building regulations. Installers registered with a competent-person scheme such as FENSA or CERTASS can self-certify the work and issue the certificate you will need when you sell. Confirm each firm is registered before comparing on price.

5. Read the small print

Watch for deposits, staged payments, finance terms and how long the quote is valid. Be wary of high-pressure “today only” discounts — a fair price does not expire at the end of a sales visit. For a deeper walkthrough of reading quotes, this guide to how to compare window quotes line by line is a useful companion.

Homeowner reviewing window quotes on a laptop — Check the guarantee and accreditations, not just the bottom line.

6. Judge on value, not just price

The cheapest quote is not always the best. Weigh price against specification, guarantee and the installer's track record. Sense-check each figure against the typical ranges in our window price guide, and understand the drivers in what affects window prices. When you are ready, get matched with local firms and compare real quotes.

uPVC, aluminium and timber window samples lined up for comparison — Like-for-like means the same material, glazing and finish on every quote.

Common quote pitfalls to avoid

A few traps catch homeowners out again and again. The first is comparing a supply-only price against a supply-and-fit one — always confirm both quotes include fitting and making-good. The second is a headline discount that only applies “if you sign today”; a genuinely fair price does not vanish overnight, so never let a deadline rush your decision. The third is a vague specification: if a quote does not state the material, glazing and finish clearly, ask for it in writing before you compare.

It also pays to look beyond the numbers. Check how long each firm has been trading, ask to see examples of previous work, and confirm the guarantee is insurance-backed so it survives if the company stops trading. A slightly higher quote from an established, accredited installer with solid cover can be far better value than the cheapest headline figure from an unknown firm. Comparing on this full basis is what turns three quotes into a confident decision.