uPVC vs Composite vs Aluminium, an Honest Comparison

Where uPVC wins

uPVC is the warmest material per pound spent. A modern multi chamber profile with steel reinforcement gives an A rating, twenty years of service and a price no other material matches. Its weakness is sightline. The frame is thicker than aluminium, so on a very large opening you lose more glass area, and on a period stone front a chunky chamfered profile can look wrong unless you go for a flush sash.

Where aluminium wins

Aluminium is strong enough to hold a very large pane in a very slim frame, which is the whole reason to choose it. Thermally broken systems close most of the old thermal gap, and the powder coated finish is tougher than any foil. It costs more, and on a small window the slim sightline advantage is invisible, so it earns its money on big rear elevations, bi folds and sliding doors rather than on a standard bedroom window.

Where composite wins

Composite is a door material rather than a window material. The 48mm timber and foam core inside a glass reinforced plastic skin gives you rigidity that neither uPVC nor aluminium matches at door sizes, along with the best thermal performance of the three on a front entrance. It is why we fit composite on the front and often uPVC on the back.

A sensible mix for a South Wales house

On a typical Valleys or Cardiff property we would specify composite on the front door, uPVC casements or flush sash on the front and side elevations where cost per opening matters, and aluminium on the rear where a large glazed opening onto the garden is the feature of the house. That combination costs far less than aluminium throughout and looks better than uPVC throughout.

• Front door, composite for security and warmth
• Bedroom and front elevation windows, uPVC for value and thermal performance
• Rear sliding or bi fold, aluminium for slim frames and big glass
• Conservation or stone fronted properties, uPVC flush sash for a period sightline