uPVC vs Timber Windows: Complete UK Comparison Guide

It depends on your local authority's policies. Some councils accept high-quality uPVC with authentic detailing (slim sightlines, run-through horns, mechanical joints, woodgrain finish) for unlisted buildings in conservation areas. Others require timber. Always check with your local conservation officer before ordering. Installing non-compliant windows can result in enforcement action and the requirement to remove them at your own cost.

Softwood timber windows need repainting every 3-5 years, while hardwood windows can go 5-7 years between coats. The frequency depends on exposure — south and west-facing windows weather faster. Using modern microporous paint systems (such as Sadolin or Teknos) extends the recoating interval compared to traditional gloss paint. A professional repaint costs approximately £40-£80 per window, while DIY costs around £15-£30 per window in materials.

The difference is minimal in practice. uPVC achieves slightly better U-values in most configurations (1.2 vs 1.3 W/m²K), but the real-world energy cost difference is approximately £10-£20 per year for an average home. Both materials comfortably meet Building Regulations Part L requirements and can be specified with identical glazing units. Timber may offer slightly better acoustic insulation due to the denser frame material.

For painted finishes, engineered Scandinavian redwood (Scots pine) is the most popular and cost-effective choice. For premium projects, hardwoods such as sapele, European oak, or Accoya (acetylated radiata pine) offer superior durability and require less frequent maintenance. Accoya is increasingly popular as it combines the sustainability of softwood with the durability of hardwood, offering a 50-year guarantee above ground.

Yes, they can. Estate agents report that uPVC windows on a period property (pre-1930s) can reduce its value by 5-10%, particularly in desirable areas with a high proportion of well-maintained period homes. Conversely, high-quality timber windows can add significant value. For Victorian and Edwardian properties, the window style is one of the most prominent architectural features and contributes significantly to kerb appeal.

Yes, this is one of timber's key advantages. Rotted sections can be cut out and new timber spliced in using epoxy resin and timber splice techniques. Individual components — sills, rails, stiles — can be replaced without replacing the entire window. A specialist joiner can repair a timber window for £150-£400, compared to £800+ for a full replacement. This repairability is why conservation bodies recommend repair over replacement wherever possible.

Most uPVC windows last 20-30 years before requiring replacement. Early signs of ageing include yellowing or greying of the plastic, seal failure causing misted double glazing, difficulty opening/closing due to profile distortion, and cracking around welded joints. Premium uPVC systems from established manufacturers (such as REHAU, Deceuninck, or VEKA) tend to last towards the upper end of this range.

Yes, timber windows are one of the most sustainable building products available. Wood is renewable, biodegradable, and stores carbon (approximately 15-25kg CO2 per window frame). When sourced from FSC or PEFC certified forests, the timber used for windows comes from sustainably managed forests where more trees are planted than harvested. The long lifespan of timber windows (60-100+ years) further enhances their sustainability credentials.

The most convincing woodgrain uPVC finishes are 'Irish Oak' and 'Golden Oak' from major systems companies. For a more contemporary look, 'Anthracite Grey' woodgrain and 'Rosewood' are popular choices. Mechanically jointed uPVC frames (where corners are joined with a mortise rather than welded) provide the most realistic timber appearance, as they eliminate the visible welded corner that is a telltale sign of uPVC.

You do not personally need FENSA registration, but your installer should be FENSA registered (or registered with an equivalent competent person scheme like CERTASS). This allows them to self-certify that the installation complies with Building Regulations, providing you with a certificate that is required when selling your property. If you use a non-registered installer, you must apply to your local authority for Building Control approval at a cost of approximately £200-£400.