Double glazing quote checklist

Two quotes can look wildly different simply because they are pricing different things. The fairest way to compare double glazing is to make sure every installer is quoting the same specification, the same scope and the same guarantee. This checklist gives you the questions to ask.

Get the specification straight

• Frame material and range. uPVC, aluminium or timber — and which product range, since quality varies within each.
• Glass specification. The energy rating, whether warm-edge spacers are used, and any acoustic, toughened or obscure glass where you need it.
• Style and opening. Casement, sash, tilt-and-turn, bay or bow, and how many opening lights per window.
• Colour and finish. Woodgrain foils and non-white colours can change the price, so specify them up front.

Our prices guide explains how each of these choices moves the number, so you can set a consistent spec before the surveyor arrives.

Confirm the full scope

• Removal and disposal of your old windows.
• Making good internally and externally around the reveals.
• Any scaffolding or access equipment for upper floors.
• Building regulations compliance and the FENSA or CERTASS certificate.

Check the guarantee and the company

Ask what the guarantee covers, how long it lasts and whether it is insurance-backed so it still stands if the company ever ceases trading. Confirm the installer is accredited to a recognised scheme, ask about deposit protection, and check whether the survey and quote come with any obligation to proceed (with us, they never do).

Read the price the right way

Once every quote covers the same spec, scope and guarantee, you can compare on total cost with confidence. Watch for extras hidden below the headline figure, and be wary of a price that only holds "if you sign today" — our guide to avoiding pressure sales explains why a fair price does not expire. Understanding how double glazing is priced helps you sense-check each line.

Before the surveyor arrives

A little preparation makes every quote more accurate. Walk round your home and note which windows you want replaced, their rough sizes and any that are bays, bows or awkward to reach. Decide your priorities in advance — energy efficiency, security, noise reduction or a particular style — so you can brief each installer the same way. Clear access to each window on survey day helps the surveyor measure properly, and having your questions written down means nothing gets forgotten in the moment.

After you receive the quotes

Once the quotes land, line them up side by side and check each one covers the same specification, scope and guarantee before you look at the totals. Query anything that seems missing or unusually cheap, and confirm the lead time from order to fitting. Take your time comparing — a fair quote does not expire overnight, and our guide to avoiding pressure sales explains why you should be wary of any that supposedly does. When every offer is truly like-for-like, the best value becomes obvious.