Fenestration
Aluminium and PVC Window Systems Compared
Aluminium and PVC solve the same problem in opposite ways: one carries load and manages heat through an inserted break, the other insulates through chamber geometry and reinforces to reach size.
Structure
Aluminium is structural. It supports tall leaves and long spans in slender sections, which is why minimal-sightline and large-opening architecture relies on it.
PVC reaches size through steel or composite reinforcement inside the profile. Beyond a certain sash weight and span, aluminium becomes the appropriate choice.
Thermal behaviour
Aluminium conducts heat, so thermally broken systems insert an insulating barrier between interior and exterior sections of the frame. The depth and continuity of that break govern the result.
PVC has low conductivity and uses multi-chamber geometry to interrupt heat flow without an inserted break.
In both cases the glazing build-up usually contributes more to overall performance than the frame does.
Choosing between them
The decision is usually made against four factors.
- —Opening size and sightline ambition
- —Thermal target for the climate zone
- —Exposure, including coastal corrosion
- —Budget and the programme's volume