uPVC Windows: What You Need to Know
uPVC has dominated the UK window market since the 1980s. It does not rot, does not need painting and resists salt-air corrosion well. Modern uPVC profiles include titanium dioxide as a UV stabiliser, which prevents the yellowing that affected earlier products. Multi-chamber frames with five or more internal chambers provide good thermal performance.
Costs
A standard uPVC casement window costs £450 to £700 installed. Timber equivalent: £700 to £1,200. Aluminium: £500 to £900. Colour options now extend well beyond white — anthracite grey and woodgrain foil finishes add around 10 to 15% to the price.
Styles Available
- Casement: standard side-hinged, suitable for most properties
- Tilt-and-turn: hinge at bottom for ventilation or fully inward for cleaning
- Sash: vertical sliding, traditional appearance
- Bay: three or more angled panes
Glass Specification
Standard double glazing uses two panes with an argon-filled gap of 16 to 20mm. Low-emissivity (Low-E) glass is standard in A-rated windows and reflects heat back into the room. Laminated glass holds shattered panes together and is worth specifying for ground-floor windows. Toughened glass is a legal requirement in some locations under Building Regulations Part N.
Planning Permission
Like-for-like window replacements do not usually require planning permission. Exceptions include conservation areas, listed buildings, and properties with Article 4 Directions removing permitted development rights. Check with your local planning authority if in doubt.
Lifespan
Good-quality uPVC windows last 20 to 30 years. Annual maintenance is minimal: wipe frames with soapy water, oil hinges with light machine oil, inspect silicone seals for cracks. Failed sealed units (misted internally) need the glass unit replaced rather than the whole frame, typically £80 to £150 per unit.
