For domestic applications, the W30 system is B-rated by the BFRC. Each B-rated window incorporates an 18mm double glazed unit, comprising 4mm soft coat low e glass and 4mm clear low iron glass sandwiching a 10mm krypton gas-filled cavity with a warm edge spacer bar.
In addition to the outstanding overall thermal performance of the window, the W30 is double weather-stripped to improve weather tightness and thermal efficiency while a chamfered aluminium beading system secures the double glazed units.
To prevent any rusting, the steel elements are galvanised and the windows are powder coated to stop further decoration being required.
Various glazing decoration choices are available, including a special back-to-back spacer system to replicate original small or horizontal pane designs.
Applied leading is available using a range of lead thicknesses to simulate traditional diamond or rectangle leaded lights in a double glazed window.
From a lifecycle perspective, all the steel elements of the W30 are ultimately completely recyclable. The credentials of steel windows are recognised by the Building Research Establishment’s ‘Green Guide’, which gives them an above average B rating.