UK price guide · Updated 26 Sep 2026
Double vs Triple Glazing Cost
On the same medium 1200×1200 white uPVC window, the current model centres around £526 with standard double glazing and £615 with triple glazing. That is roughly 17% more in this specific example.
Current price examples
These examples use the same current pricing engine as the calculator. They are market estimates rather than binding installer quotations.
Why triple-glazing premiums vary
There is no defensible single percentage that works across every product. Extra glass weight, unit thickness, frame system, sash size and installation effort vary. The calculator therefore uses product-specific triple-glazing adjustments instead of one blanket uplift.
Cost is not the same as value
A lower U-value can improve thermal performance, but glazing choice should be considered alongside frame performance, whole-window U-value, orientation, comfort and the rest of the specification. The price calculator models cost; it does not claim that the most expensive option is automatically the best choice for every property.
What affects the price?
- Same frame and size comparison
- Product-specific glazing premium
- Whole-window performance rather than glass alone
- Weight and hardware implications on opening sashes
What “fitted” means here: supply, standard replacement installation and ordinary 20% VAT are included. Unusual access, scaffolding, structural repairs, planning/listed-building requirements and highly bespoke work can sit outside the standard estimate.
Related price guides
Compare the closest related costs, then use the calculator for your own specification.
Questions people ask
Short answers to the most useful questions around this price topic.
How much more does triple glazing cost?
For the medium standard uPVC example, the centre rises from about £526 to £615, around 17%. Other product types use different uplifts.
Is triple glazing always 17% more?
No. The uplift varies by product, size and system. The calculator does not apply one universal percentage.
Does the comparison include fitting?
Yes. Both examples are fitted-market estimates including ordinary VAT.
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