Secondary Glazing Cost2026 Price Guide
Secondary glazing typically costs between £300 and £2,200 per window depending on the glass specification. This guide breaks down the price per window and for a whole home, and explains exactly what drives the cost.
Cost Per Window
The single biggest factor in your quote is the glass specification. Here is what to budget per window in 2026:
| Specification | Price per window | Best for |
|---|---|---|
| Standard (4mm float glass) | £300 – £800 | Thermal comfort and light noise reduction |
| Acoustic (10.8mm laminate) | £600 – £1,200 | Homes near traffic, railways or flight paths |
| Heritage grid-matched | £1,000 – £2,200 | Listed buildings and period sash windows |
Whole-Home Cost
Most homeowners glaze several windows at once. As a guide, here is what a typical project costs by property type:
| Property | Typical windows | Estimated range |
|---|---|---|
| Studio / 1-bed flat | 4 – 6 windows | £2,500 – £6,000 |
| 2 – 3 bed flat or maisonette | 6 – 10 windows | £5,000 – £12,000 |
| Period townhouse | 12 – 20+ windows | £12,000 – £30,000 |
What Affects the Price?
- Glass specification. Standard float glass is the most affordable; 10.8mm acoustic laminate costs more but delivers the best noise reduction.
- Opening style. Fixed panels are cheapest, while sliding and hinged units cost more for the added mechanism.
- Window size. Larger and bay windows use more material and take longer to fit.
- Heritage detailing. Grid bars matched to original sashes add cost but preserve the look of period and listed buildings.
How It Compares to Replacement Windows
The headline figures are only half the story. Replacing a single timber sash window with a heritage-appropriate double-glazed equivalent typically runs into several thousand pounds per window once you account for manufacture, removal, making good the surrounding plaster and redecoration. Secondary glazing sits well below that because the original window stays exactly where it is — there is no rip-out, no structural work and no redecorating bill afterwards.
For a whole period property the gap widens considerably, and in a listed building or conservation area replacement is often refused outright, which makes the comparison academic. You should also factor in the cost of not acting: a leaky single-glazed window keeps inflating your heating bills every winter and lets condensation attack the original timber, and timber repairs are far more expensive than prevention.
Is It Worth the Investment?
Because secondary glazing cuts heat loss through the window by more than 60%, most homeowners see a meaningful reduction in their heating costs, and the benefit compounds every year that energy prices rise. The returns that clients tell us matter most, though, are the ones that do not appear on a bill: sleeping through the night on a main road, using a cold bay window in January, and no longer wiping condensation off the glass each morning.
We would rather be straight with you than oversell it. If your primary frames are already rotten or structurally unsound, secondary glazing will not fix that underlying decay — the timber needs restoring first, or you are simply glazing over a problem. Equally, if you own an unlisted property outside a conservation area and have no objection to modern replacement windows, that may be the better long-term route. But if you want to keep original windows that cannot or should not be replaced, this is the most cost-effective upgrade available. Every quote is fixed, itemised and follows a free no-obligation survey, so there are no surprises.
For a deeper breakdown, read our full 2026 secondary glazing price guide, find out whether it is worth it, or return to our complete guide to secondary glazing.
Secondary Glazing Cost: Frequently Asked Questions
Common questions about secondary glazing prices, what's included, and how to get an accurate quote.
What Our Clients Say
Rated 4.9 out of 5 across 127 reviews from London homeowners.
"Exceptional service from start to finish. The noise reduction in our Kensington townhouse is remarkable — we no longer hear the constant traffic on the high street, even in the front bedrooms."
"Specialists who truly understand listed buildings. They handled our Grade II* property with real expertise and managed the conservation paperwork so we didn't have to worry about a thing."
"Our Georgian sash windows were draughty and freezing every winter. The secondary glazing has transformed the house — warmer rooms, lower heating bills, and the original windows look untouched."
"From survey to installation the team was professional and tidy. The fit is so discreet that visitors don't even notice the secondary glazing is there. Sleep has never been better."
"We live near a busy junction and the difference is night and day. The acoustic glass they recommended cut the noise dramatically. Worth every penny for the peace and quiet."
"Honest advice, fair pricing, and beautiful craftsmanship. They talked us through every option without any pressure. I would recommend them to anyone with a period property."
Get an Accurate, Itemised Quote
Price guides are a starting point — the only way to know your exact cost is a free survey. We measure every window and give you a clear, no-obligation breakdown.