Decision Tools
The calculators answer "how much". These two tools answer the other questions: am I eligible, and is this quote any good?
Where our calculators tell you what double glazing should cost, the tools here help you make the decisions around the purchase. The grant eligibility checker works through the 2026 schemes to tell you whether it is worth applying, and the quote quality auditor checks a quote against what a proper install should include. Use them alongside the price ranges, not instead of them.
Grant Eligibility Checker
Answer a few questions to see whether you might qualify for a 2026 energy grant towards windows.
Quote Quality Auditor
Paste in the details of a quote and check it against the things a good install should include.
Tools versus calculators
Keep the two apart in your head. A calculator answers "how much will this cost", so reach for the uPVC window calculator when you want a number. A tool answers "should I" or "which one": whether you might qualify for help (see our grants guide for the detail behind the checker) or whether a quote is fair (read how to avoid being overcharged alongside the auditor). Used together they cover both the price and the decision.