Quotes
Getting an energy-saving glazing quote
Two quotes for “energy-efficient double glazing” can hide very different glass. One might specify a soft-coat low-E, an argon fill and a warm-edge spacer; the other might be a plain unit dressed up in the same words. The way to compare fairly is to look past the headline price at the specification. This guide lists what to ask for on an energy efficient glazing quote so you can judge suppliers on the tech — where the real savings live — and not just the number at the bottom.
Ask for the glass specification
A good quote names the parts of the sealed unit rather than hiding behind “A-rated”. Look for:
- The low-E coating — the product and which pane it sits on. See soft vs hard coat low-E glass.
- The gas fill — argon as a minimum, or krypton for slim units. Read argon vs krypton gas-filled units.
- The spacer bar — warm-edge, not aluminium. See warm-edge spacer bars explained.
- The cavity width — a sensible spacing matched to the gas, per cavity width and performance.
Check the numbers
Ask for the whole-window U-value and the Window Energy Rating, and make sure they are quoted for the finished window, not just the centre of the glass. Those figures are how you compare units on measured performance rather than marketing language. To read them properly it helps to understand U-values and window energy ratings explained, and if the sun reaches your rooms, the g-value is worth a mention too.
Look at the whole job, not just the units
The installation matters as much as the glass. Ask what frame and material are proposed — and match the tech to your frame material, since a good unit in a poor frame underperforms. Check that fitting, making good, removal of the old windows and certification under the building regulations are all included, along with the guarantee on both the units and the workmanship. A clear, itemised quote is a good sign; a vague one is worth questioning. Our overview of what to look for on a glazing quote goes through the detail.
Costs, funding and value
Get more than one quote so you have something to compare, and weigh the specification against the price rather than picking the cheapest by reflex. If the upfront cost is the obstacle, funding and contribution options may be available subject to eligibility and a home survey, and £0-upfront options may be available for those who qualify; you can also spread the cost with funded glazing. To set expectations on the return, our double glazing payback period guide explains how the savings stack up over time, using attributed ranges.
Then let a survey confirm it
No online figure beats a home survey for accuracy: it accounts for your actual windows, frames and openings. Once you know what to ask for, requesting a free, no-obligation quote is quick, and you can hold each supplier to the same specification.
Any savings, energy or payback figures on this page are indicative typical ranges from Energy Saving Trust and manufacturer data, not guarantees — your own result depends on your home and the units you choose.