The most common question when replacing windows: aluminium or PVC? We compare the two on insulation, strength, appearance, lifespan and cost.
On new builds and window replacements, the question we hear most is: aluminium or PVC? Both materials have strengths. The right choice depends on the building type, opening sizes, architectural intent and budget.
Thermal insulation
In the past, aluminium’s weak point was thermal conductivity. Today, thermally broken (polyamide-separated) aluminium profiles reach insulation values that compete with PVC. With the right glazing, both materials can deliver high energy efficiency.
Strength and slim profiles
Aluminium is far stronger than PVC, so slimmer sections can carry larger glass areas. For large sliding doors, corner panoramic windows, shop fronts and commercial facades, aluminium is the clear winner.
Lifespan and appearance
Aluminium does not yellow in sunlight or deform, keeping its original form for decades. Powder coating offers every RAL colour, wood-grain finishes and anodised surfaces.
Comparison
| Criterion | Thermally broken aluminium | PVC |
|---|---|---|
| Thermal insulation | Very good | Very good |
| Strength | Very high | Medium |
| Large openings | Suitable | Limited |
| Profile slimness | Slim | Bulky |
| Colour options | Unlimited | Limited |
| Recyclability | 100% | Limited |
| Initial cost | Higher | Lower |
Which for which building?
- Offices, shops, hotels, villas and modern homes: thermally broken aluminium for large glass and slim frames.
- Standard-size residential windows on a tight budget: PVC can be a sensible option.
- Joinery integrated with curtain walls: aluminium for system compatibility.
Installation matters as much as material
Whatever you choose, installation quality determines performance. Without mechanical anchors, expansion tapes and vapour-control membranes, air and water leaks are inevitable.
Learn more on our Aluminium Joinery Systems page.
Get expert advice for your project
Let’s assess whether the systems described here suit your building, with a free site survey.
