Collection: Timber Windows

Timber windows outperform uPVC in thermal efficiency, environmental credentials, and longevity when properly maintained.

Timber is a naturally superior insulator, enabling lower whole-window U-values than PVC frames. Sustainably sourced timber is a renewable material with significantly lower embodied carbon than uPVC and is biodegradable at end of life.

Triple glazing is not always required, but it is usually necessary to achieve whole-window Uw values below 1.0 W/m²K in a timber frame.

Double-glazed timber windows typically achieve Uw values of approximately 1.0–1.3 W/m²K with warm-edge spacers and Low-E glass. For Passive House and low-energy projects targeting below 0.80 W/m²K, triple glazing is required.

For window applications, engineered (laminated) timber is preferable to solid-sawn timber.

Laminated construction is dimensionally more stable – it reduces the risk of warping, twisting, or moisture ingress over time – and typically delivers more consistent long-term performance. Norrsken uses laminated timber frames as standard across the range.

Timber windows require periodic inspection and repainting or restaining, typically every five to ten years depending on exposure and finish quality.

Norrsken's timber windows receive multi-coat protection treatment in manufacture, extending the time between maintenance cycles. For minimal external maintenance, alu-clad windows provide a practical alternative with an identical timber interior. Hardware should be inspected and maintained at least twice per year to ensure smooth operation long-term.

Well-maintained laminated timber windows can last 50 years or more. The key variables are timber quality, finish protection, installation detailing, and user maintenance and care. Norrsken uses precision-engineered laminated timber, which significantly improves dimensional stability and moisture resistance compared to solid-sawn equivalents.

Timber windows are frequently the preferred – and in some cases required – specification in conservation areas, where planning authorities may restrict uPVC or aluminium. Norrsken's timber windows can be specified with traditional configurations, period-appropriate glazing bar profiles, and heritage-style hardware. Specific planning requirements should be confirmed with the local planning authority at the design stage.

Yes, in most whole-life assessments. Responsibly sourced timber has significantly lower embodied carbon than uPVC or all-aluminium alternatives, a longer typical service life than uPVC, and better end-of-life characteristics than both. For projects with embodied carbon targets or sustainability accreditation requirements, timber is the most defensible specification. Manufacturer EPD certificates provide verified data for project-level whole-life comparisons.

Yes. Norrsken's triple-glazed timber windows achieve whole-window Uw values around 0.70 W/m²K – below the Passive House Institute's threshold of 0.80 W/m²K.

The 88mm laminated timber frame accommodates a 50mm triple-glazed unit with argon gas fill, warm-edge spacer bars, and dual Low-E coatings. Full PHPP-compatible data is available for the range.