Technical Specifications
System Alitherm 300 / Alitherm 400 / Cortizo COR 70
Material Aluminium with Polyamide Thermal Break
Frame Depth 53mm (Ali 300) / 70mm (Ali 400 & COR 70)
U-Value (Double Glazed) From 1.3 W/m²K (COR 70) to 1.5 W/m²K (Ali 300)
U-Value (Triple Glazed) From 0.9 W/m²K (COR 70) to 1.2 W/m²K
Glazing Thickness 24mm – 45mm (double or triple)
WER Rating A-rated achievable across all systems
Security PAS 24:2022 approved
Weather Performance BS 6375-1:2009 compliant
Air Permeability Class 4 (600 Pa)
Water Tightness Class AE 2400
Wind Resistance Class 2000+
Max Sash (Side Hung) 700mm x 1400mm (Ali 300) / 1200mm x 3500mm (COR 70 HD)
Acoustic Rating Up to 45 dB Rw
Document L Compliant Yes
All our aluminium casement windows are available with a choice of high-performance glazing to suit your project requirements:
We specify the optimal glass configuration for each project based on thermal performance, acoustic requirements and Building Regulations compliance.
Colours & Finishes
All our aluminium casement windows are powder coated using a Qualicoat-certified process and are available in the full RAL colour palette — over 200 standard colours plus bespoke colour matching for heritage and commercial projects.
A different colour can be applied to the internal and external faces of any frame — allowing the exterior to meet planning requirements or match the building's facade while the interior colour coordinates with the internal design scheme.
Dual-colour finishes are a popular choice for windows — anthracite grey or black externally with a clean white internal finish to match your interior.
Anodised aluminium provides a harder, more scratch-resistant surface than powder coat and is available in natural silver, bronze, champagne, and dark grey anodised finishes — commonly specified for commercial projects, high-traffic environments, and where a metallic appearance is required.
RAL and NCS colour matching is available for projects requiring an exact match to an existing material, manufacturer specification, or architect's colour schedule. Samples are available on request prior to order.
Explore common questions about our Aluminium Casement Windows, suitable for both residential and commercial properties. Discover how these windows offer durability, performance, and energy efficiency.
Get a Free Quote for Alitherm Heritage Casement WindowsAluminium casement windows are a versatile window system suitable for both residential and commercial properties. They can be installed in various settings, including homes, offices, and other commercial buildings.
These casement windows offer versatility with options such as fixed, single or double sash, top hung, tilt & turn, or pivot styles. They are thermally efficient thanks to a polyamide thermal break, built for long-term durability, and equipped with full PAS24 accreditation for security.
Yes, you can. Depending on your needs, you can choose from a variety of dimensions for side hung, top hung, and fixed casement windows, providing flexibility for different project requirements.
Yes, these casement windows, particularly using Smart's Alitherm models, are ideal for projects that require planning permission due to their versatile and high-quality design.
