U8 – A quadruple glazed passive approved unit. Glass construction from outside to inside is 4H-Tg12Kr-4HT-Tg12Kr-4HT-Tg12Kr-4HT. The outer pane is a 4mm toughened glass and has a 12mm warm TGI spacer filled with inert krypton gas. The 4mm centre pane is toughened with a low emission coating. This glazing unit produces a U-Value of 0.64W/m²K.