
A Light-Weight, High-Strength and Cost-Effective
Alternative to Traditional Steel Window and Door Systems
Alitherm Heritage Windows
Get a QuoteAlitherm Heritage windows and doors offer an exceptional solution for homeowners looking to retain their property’s classic character while benefiting from modern performance. Perfect for sensitive refurbishments and renovations, these profiles seamlessly blend the timeless look of steel with the advantages of contemporary aluminium.
Why Choose Alitherm Heritage Windows?

Durable & Long-Lasting
Aluminium is renowned for its robustness and resistance to rust and rot, making it an excellent long-term investment. Unlike traditional materials, these frames have an impressive lifespan, often indefinitely.
Enhanced Thermal Efficiency
With innovative polyamide thermal break technology, Alitherm Heritage windows and doors provide superior insulation, preventing heat loss and helping homeowners save approximately £95 annually on energy bills.


Low Maintenance
Say goodbye to laborious upkeep. Aluminium frames only need a simple wipe clean to stay pristine. No repainting or varnishing is required, and they will never fade or deteriorate over time.
Windows Tailored for Heritage Homes
The Alitherm Heritage aluminium windows range is thoughtfully designed for listed properties and homes requiring authentic aesthetics. The modular construction allows for versatile configurations, including:
- Fixed windows
- Single or double sash windows
- Side-hung or top-hung casement windows
- Tilt-and-turn and pivot windows

These windows feature slim sightlines and a polyamide thermal break, ensuring exceptional thermal performance while preserving heritage styling. Each unit has a marine-quality, polyester powder-coated finish in single or dual colours.
Elegant Alitherm Heritage Doors
For homeowners wanting to replace old steel balconies or entry doors, Alitherm Heritage doors are the perfect match. Their elegant design includes signature slim sightlines that emulate classic steel, easily meeting conservation area requirements.
Key features include:
- Available in single or double-door configurations
- Multi-point locking systems for enhanced security
- Face-mounted shoot bolts and slim, tape or gasket glazing

Create stylish entrances with Alitherm Heritage. It combines the charm of yesteryear with the benefits of modern aluminium, including thermal breaks and customisable hardware options.
Unmatched Performance & Certifications
Alitherm Heritage products come with high-performance ratings, ensuring peace of mind:
- WER Rating: B
- U Value: 1.5 W/m²K (with 1.0 W/m²K sealed unit)
- Air Tightness: Class 4, 600Pa
- Water Resistance: Class 9A, 600Pa
- Wind Resistance: Class AE, 2400Pa
- Security Certification: PAS 24:2016 for enhanced security