When triple glazed the system is capable of achieving an overall (frame plus glass) U-value of just 0.8W/m²K, making it suitable for even Passivhaus standard homes. The SF55s is capable of achieving 1.2W/m²K triple glazed (1.4W/m²K double glazed) meaning they comply with Building Regulations Part L for extensions, renovations and new-build homes.

A system for any requirement
Our range of aluminium bifold doors includes a solution for any type of project, from extensions and renovations to new-build eco-homes. The ultra-thermally SF75eco offers the ultimate in energy-efficient frames and is perfectly suited for those undertaking eco-home style builds. Both systems can be designed as straight sets of doors or configured with open corners or even faceted (or curved) designs for a real wow-factor.

Keeping the weather out
With bifold doors, it's not just about keeping the heat in — it's about keeping the elements out.

That’s why our SF75eco bifold doors are put through rigorous, independent lab testing to measure their resistance to air, water, and wind. Unlike most bifolds, the SF75eco features double rebated seals - a rare design detail that delivers exceptional weather protection. It’s a game-changer for homes in exposed rural or coastal locations, but a smart upgrade for anyone who wants better performance.

Exclusive antiSLAM panel catch
Holding bifold doors open safely is essential and the exclusive antiSLAM panel catch, refined over 30+ years of innovation, securely holds the lead panel in place when the doors are open. It prevents accidental slamming in windy conditions, protecting both users and the door system itself.

This smart mechanism also ensures the doors fold and operate as designed, reducing wear on hinges and hardware for smooth, reliable performance - year after year.