Reading a technical window quote

A good window quote is a technical document, not a scribbled total. Once you know how it is structured, you can see exactly what you are paying for — and spot the gaps that separate a thorough quote from a vague one.

The anatomy of a quote

Most professional quotes work through the same sections. Read them in this order and nothing should be a surprise.

1. Units, sizes and styles

Each window is listed as a line item with its opening size (usually width × height in millimetres), style (casement, tilt-and-turn, sash and so on) and opening configuration — which sashes open and which way. Check the sizes against your rooms and confirm any obscured or fire-escape requirements are noted.

2. Glazing specification

This is where the sealed unit is defined: the pane build-up, any low-E coating, the gas fill and the spacer. You might see a code such as 4–20–4, meaning a 4mm pane, a 20mm gas-filled cavity and another 4mm pane. If laminated or acoustic glass is included, it should say so here. Our guide to glass coatings and gas fills decodes this line.

3. Thermal and rating figures

Look for the whole-window U-value and, where given, the energy rating. Make sure the U-value quoted is whole-window, not centre-pane — a common point of confusion.

4. Hardware and security

The quote should name the locking system (multi-point), handle type and any reinforcement, plus whether the windows meet PAS 24. Hinges, restrictors and trickle vents — now required for ventilation in many replacements — belong here too.

5. Fitting, making good and removal

A complete quote states what the fitting price includes: removal and disposal of the old windows, internal and external making good, and any scaffolding. “Supply only” versus “supply and fit” is a frequent source of misleading comparisons, so check which you are being quoted.

6. Guarantees, certification and terms

Finally, the quote should set out the guarantee period, FENSA or CERTASS certification, whether an insurance-backed guarantee is offered, deposit terms and any deposit protection. Funding or contribution options, where mentioned, should be described as subject to eligibility and a home survey — never as a fixed saving.

Turning a quote into a decision

With every quote broken down this way, comparison becomes straightforward: the same rows, filled in side by side. That is exactly the method in comparing window specs fairly. It also helps to understand how the quoting process itself varies — there are trade-offs to getting window quotes online versus in-home, and you can get double glazing quotes across the UK to build up a picture. For anything unfamiliar on the page, the window specifications hub has the definitions.