Aluminium Windows in Cold South Island Regions. What Actually Works.

Aluminium dominates the South Island market. Performance varies widely.

The difference is not brand. It is specification.

Non-thermally broken aluminium transfers cold directly into interiors. Condensation follows.

Comfort drops. Heating costs rise.

High-performing aluminium systems use:

• Full thermal breaks.

• Multi-stage air seals.

• Correct glazing combinations.

• Stable fixing details.

In Christchurch and Dunedin, wind-driven infiltration is a common failure point. Airtightness matters more than marketing claims.

Aluminium works when it is engineered for climate, not when it is selected on price.

Cheap systems cost more over time. That cost is paid every winter.