Alitherm 400 is a versatile aluminium window and door system engineered to deliver strong thermal performance, reliable security, and a clean contemporary appearance. It’s built around insulated profiles that help reduce heat loss, while maintaining the strength and durability associated with aluminium. The system is suitable for new builds, refurbishments, and projects where a slim, modern aesthetic is preferred.
Key Features
Thermal Efficiency
- Insulated polyamide thermal break to limit heat transfer
- U‑values as low as 1.4 W/m²K depending on glazing choice
- Capable of achieving A‑rated energy performance
Security & Compliance
- Tested to PAS 24 for enhanced security
- Suitable for projects requiring Document Q compliance
- Robust locking options for both windows and doors
Weather Performance
Designed and tested for high levels of air, water, and wind resistance
- Air permeability: Class 4
- Water tightness: up to AE2400
- Wind resistance: 2000+ Pa
Window Options
Alitherm 400 supports a wide range of window styles, making it suitable for both traditional and modern properties.
- Fixed frames
- Side‑hung casements
- Top‑hung casements
- Tilt & turn windows
- Flush casement options
- Slimmer heritage‑style sashes for a more classic look
Typical Maximum Sizes
- Side‑hung: 864 × 1400 mm
- Top‑hung: 1400 × 1400 mm
- Fixed: up to 2100 × 2100 mm
- Tilt & turn: up to 1200 × 2100 mm
Glazing Options
Compatible with 24–45 mm glazing units, including double and triple glazing.
Door Options
The Alitherm 400 door system is designed to match the window range, offering a consistent appearance across the property.
- Single or double doors
- Open‑in or open‑out configurations
- Multiple locking systems including key‑wind, lift‑lever, and slam‑lock options
- PAS 24 security available
Colours & Finishes
A wide selection of finishes is available, including:
- Full RAL colour range
- Dual‑colour frames (different inside and outside)
- Textured and anodised‑effect finishes
Where Alitherm 400 Works Best
This system is ideal for:
- Residential homes
- Schools and public buildings
- Offices and commercial spaces
- New‑build and renovation projects
Its combination of performance, flexibility, and clean design makes it a popular choice for installers, architects, and homeowners.
In Summary...
Alitherm 400 offers a strong balance of energy efficiency, security, and modern styling. With multiple window and door configurations, wide colour choices, and reliable weather performance, it provides a dependable aluminium solution for a broad range of projects.