Windows
Replacement windows
Replacement windows in the UK cost roughly £400 to £1,800 each supplied and fitted, depending on material and style. uPVC is the cheapest, aluminium gives the slimmest frames, and timber is usually required on listed buildings. All replacements must meet a U-value of 1.4 W/m²K or Window Energy Rating band B.
Two decisions drive almost all of the cost: what the frame is made of, and how the window opens. Everything else is detail. Start with the material, then pick the style that suits the building.
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uPVC windows
£400 – £850 fitted
uPVC windows cost £400 to £850 fitted. What separates a good one from a cheap one, what the regulations require, and when uPVC is the wrong choice.
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Aluminium windows
£600 – £1,250 fitted
Aluminium windows cost £600 to £1,250 fitted. Why the slim sightlines matter, what a thermal break does, and whether the extra over uPVC is worth it.
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Timber windows
£800 – £1,600 fitted
Timber windows cost £800 to £1,600 fitted. Why modern engineered timber is not the wood you remember, the real maintenance, and when it is compulsory.
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Casement windows
£400 – £850 fitted
Casement windows are the most common UK style and the cheapest to replace. Side-hung or top-hung, fire escape rules, and flush versus stormproof.
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Sash windows
£800 – £1,800 fitted
Sash windows cost £800 to £1,800 fitted. Cords and weights versus spiral balances, when repair beats replacement, and fitting double glazing.
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Tilt and turn windows
£400 – £850 fitted
Tilt and turn windows open two ways: a secure vent, or fully inwards for cleaning and escape. Why flats and upper floors usually choose them.
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Bay and bow windows
£1,500 – £3,000 fitted
Bay and bow windows cost £1,500 to £3,000 fitted because many carry structural load. The difference between them and what a survey must check.
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Flush casement windows
£400 – £850 fitted
A flush casement sits level with the frame for a traditional line. What it costs over stormproof, the weathering trade-off, and why planners accept it.
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Triple glazing
£450 – £1,600 fitted
Triple glazing costs £450 to £1,600 per window fitted. What the third pane actually buys over good double glazing, and when it is worth the money.
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Secondary glazing
£400 – £1,800 fitted
Secondary glazing fits inside the existing window. Usually the best option for noise, and often the only one permitted in a listed building.
Choosing
Choosing in the right order
Decide the material first, because it sets the budget and is the decision a conservation officer cares about. uPVC is the default, aluminium buys slim frames and large panes, timber is usually compulsory on listed buildings.
Then decide the style. Casement covers most UK houses, sash is correct for Georgian through Edwardian, tilt and turn suits flats and upper floors, and bay windows carry structural load and need designing accordingly.
Only then worry about glazing. Triple glazing is a real improvement but a smaller one than it is usually sold as, and in a listed building secondary glazing may be the only route open to you.