Aluminium and steel are both metal windows, but they suit different openings. Here is how they compare for a Kerala house.
Strength and security
Steel is about three times stiffer than aluminium, so steel frames stay slim and rigid with the security grill built into the frame. Aluminium windows usually need a separate grill fixed outside or inside.
Sliding and large glass
Aluminium's extruded profiles are well suited to sliding windows, sliding doors and large glazed walls. Steel can slide and fold too, but aluminium systems are the common choice for very large glass panels.
Corrosion near the sea
Aluminium does not rust, but it can pit near the sea unless anodised or powder-coated. Galvanised steel relies on its zinc and paint; near the coast, choose heavier Z275 zinc and keep the paint intact.
Custom sizes and shapes
Steel windows are cut and folded to any opening — arches, odd sizes and matching door frames. Aluminium depends on the profiles available in the system you choose.
Upkeep
Aluminium needs little more than cleaning. Steel needs its paint renewed every few years on the weather side.
A practical mix
Many homes use steel door frames and steel windows with grills for bedrooms and outer walls, and aluminium for large sliding doors to the sit-out or balcony.