77IWE Open-Out Window


77IWE Open-Out Window

The government’s Future Homes Standard, set to become law in 2025, sets some challenging new targets for the energy efficiency of windows and doors. Our impressive 77IWE Open-Out system already meets those targets and is our highest performing window yet.

Insulated centre seals, high performance thermal break materials and extra insulating foams mean this is a window which can achieve impressively low U-Values even with standard double glazing

The modern slim lines and minimalist aesthetic make the 77IWE an ideal choice for new build and contemporary refurbs. The slim frames mean there’s a larger glass area to let plenty of light flood in, and there’s even a choice of inward or outward opening frames for maximum flexibility.



The 77IW window is available in top, side or bottom hung configurations, all in a standard 77mm frame depth.



The 77IW is very much a contemporary window system, but you can still match it to your own style with a range of colours, textures and customisation options – from glazing bars to leaded glass.



The system is available in a wide variety of configurations, delivering high levels of thermal performance through incorporating technologies such as high performance polyamides, insulated centre seals and profile foam insertions. The 77IWE system also fully integrates with our aluminium curtain walling and door systems.

Standard Technical Data
U value W/m²K 0.8-1.2 W/m²K
Air tightness (Pa) Class 4 (600Pa)
Water tightness (Pa) Class E1050 (1200Pa)
Wind load (Pa) Class C5 (2000Pa)