uPVC vs aluminium vs timber vs alu-clad: choosing a frame

Slim anthracite aluminium windows on a contemporary rendered and clad house

uPVC is the cheapest and needs no painting; aluminium is slim and strong for big panes; timber looks traditional and insulates well but needs re-coating; alu-clad timber pairs a timber interior with a maintenance-free aluminium outside and costs the most. With triple glass, all four can beat the Building Regulations limits.

At a glance

	uPVC	Aluminium	Timber	Alu-clad timber
Medium window, fitted	£895+	£1,495+	£1,795+	£1,895+
Typical whole-window U	0.8 to 1.0	0.9 to 1.2	0.8 to 1.1	0.7 to 1.0
Upkeep	Wash	Wash	Re-coat every several years	Outside: wash
Sightlines	Wider	Slimmest	Traditional	Medium
Lead time	4 to 6 weeks	5 to 7 weeks	6 to 10 weeks	8 to 12 weeks

uPVC

Best value and widely available. Choose a deep, reinforced system for triple glass.

Aluminium

Strong and slim, any RAL colour. Check the thermal break.

Timber

Traditional, repairable and a good insulator. Engineered timber resists warping.

Alu-clad timber

Timber warmth inside, weatherproof outside. Often chosen for self-builds.

Questions

Which frame is warmest?

Deep timber and alu-clad timber frames often perform best, but good uPVC is close.

Which frame lasts longest?

Well-maintained timber and aluminium can outlast uPVC; all should give decades of service.

Sources

More guides

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