Domestic window u-values have been tightened for new build, refurbishment and replacement windows, with greater restrictions placed on the centre pane U Value compliance route.
Window energy ratings can be significantly improved using low iron glass but it’s the frame where the overall calculation is achieved. Combination of Aluminium and timber makes all this possible where vertical sliding sash windows are required. The minimum overall u-value is 1.6 w/m2k for existing windows and 2.0 w/m2k for new build.
We have designed and developed an Alu-wood Vertical Sliding Sash (Triple Glazed) Window that is the only one manufactured in Europe, which replaces all existing sliding sash that do not achieve these new energy ratings.