High performance all wood windows: suitable for Passivhaus, zero carbon, ultra-low energy buildings in contemporary or conservation settings. Massiva are all wood construction (except for narrow aluminium capping on horizontal cill sections). KATZBECK sources all its timber from sustainable, FSC certified forests and uses environmentally friendly finishes.

Windows available with additional muntins/glazing bars and mouldings making them ideal for retro-fitting or creating new buildings in traditional styles and conservation settings but with state-of-the-art energy efficiency.

With Uw from 0.75 W/m²K .

High performance all wood windows: suitable for Passivhaus, zero carbon, ultra-low energy buildings in contemporary or conservation settings. Massiva are all wood construction (except for narrow aluminium capping on horizontal cill sections). KATZBECK sources all its timber from sustainable, FSC certified forests and uses environmentally friendly finishes.

Windows available with additional muntins/glazing bars and mouldings making them ideal for retro-fitting or creating new buildings in traditional styles and conservation settings but with state-of-the-art energy efficiency.

With Uw from 0.75 W/m²K .