Steel Look Windows, Doors & Internal Screens

Technical Specifications

Smart Systems Alitherm Heritage — the definitive aluminium system for heritage and conservation applications, delivering slimline steel-look profiles with contemporary thermal performance and full PAS 24 security certification.

Key Specifications — Alitherm Heritage (Externals)

• Thermal Performance: U-values from 1.6 W/m²K (with 1.0 W/m²K glass unit); WER Band B rated
• Frame Depth: 47mm; typical sightlines 59mm — replicating original steel proportions
• Security: PAS 24:2016 certified (casement windows and fixed lights); BS Kitemark KM 81543 and KM 81580
• Weather Performance: Air permeability Class 4; watertightness Class 7A (internal bead); wind resistance Class AE 2400 — tested to BS 6375-1:2009
• Max Panel Sizes: Fixed lights up to 2100 × 2100mm (4.2m²); doors up to 900 × 2100mm
• Glazing: Double or triple glazed units — 24, 28, 32 and 36mm options

Key Specifications — AluSpace (Internal Screens)

• Profile Depth: 35mm (main profiles); 33mm (transoms/mullions) — ultra-slim steel-look sightlines from 30.5mm
• Acoustic Performance: Up to 18mm acoustic glazing units for effective sound attenuation between zones
• Max Door Sizes: Hinged up to 900 × 2200mm; pivot up to 2000 × 2500mm; sliding up to 1200mm wide per panel × 2500mm high
• Glazing: 6mm, 8mm single or up to 18mm for acoustic applications; laminated or toughened safety glass as standard
• Finish: Full RAL powder coat palette; hardware in ten finishes including Matt Black, Antique Brass, Satin Chrome

The Steel Look range is specified across listed building refurbishments, contemporary new-build extensions, and commercial fit-outs in conservation areas throughout Surrey and West London. Alitherm Heritage satisfies conservation officer requirements for slim sightlines and period-correct proportions, while AluSpace internal screens divide open-plan interiors without compromising natural light or sightlines — both systems delivering a visually unified steel aesthetic throughout a project.

Glass Options

All our steel look windows, doors and screens are available with a choice of high-performance glazing to suit your project requirements:

• Double-glazed sealed units — standard specification for thermal efficiency
• Triple-glazed units — enhanced thermal and acoustic performance
• Acoustic laminated glass — for noise reduction in urban and roadside locations
• Solar control glass — reduces heat gain and glare while maintaining natural light

We specify the optimal glass configuration for each project based on thermal performance, acoustic requirements and Building Regulations compliance.