Aluminium windows

Why the frame material changes the window

Aluminium is stronger than uPVC and stronger than timber, so the same structural job can be done with far less frame. On a standard 1200 × 1200mm opening that difference is worth around 15–20% more visible glass — which is the single thing most people notice when the old windows come out.

The trade-off used to be heat. A bare aluminium frame conducts, and pre-1990s aluminium windows were notoriously cold. Modern systems solve that with a polyamide thermal break: a non-conductive barrier bonded between the inner and outer sections of the frame, so the cold outer face never touches the warm inner face. A current system will hit a whole-window U-value of around 1.2–1.4 W/m²K, which meets or beats Part L.

The styles we fit

• CasementSide or top-hung, opening outward. The UK default, and the cheapest way into aluminium.
• Tilt & turnTilts inward at the top for secure ventilation, swings fully inward for cleaning. Standard on apartments and above ground-floor level.
• SlidingHorizontal sliders for wide openings where an outward opening sash would foul a path or balcony.
• BayTwo, three or five-section bays — including replacing rotten timber or failed 1970s aluminium bays on 1930s semis.
• Heritage / steel-lookSlim, flat-faced profiles with a putty-line detail that replicate original Crittall steel windows closely enough for most conservation officers.
• Slimline fixedFixed lights and picture windows with minimal frame, for maximum glass.

Specification we fit as standard

• Thermal breakPolyamide, on every profile. Not optional.
• GlazingDouble glazed with a warm-edge spacer and argon fill; triple available.
• FinishPolyester powder coat to any RAL colour, matt or satin. Marine grade for coastal sites.
• SecurityMulti-point locking, internally beaded, laminated glass on ground floor where specified.
• VentilationTrickle vents where Part F requires them — see our guide.

Ranges include VAT and installation. Final price depends on size, spec, access and site condition — a survey gives you a fixed number.