PERFORMANCE triple glazed timber casement window Green Building Store


PERFORMANCE outward opening casement window

Our best-selling cost-effective triple glazed timber outward opening casement window. Uw 0.85 W/m2K.


Glazing & U values

Whole window U value: Uw 0.85 W/m2K (Redwood)
Whole window U value: Uw 0.93 W/m2K (Oak)
Glazing Ug: 0.58 W/m2K
Triple unit: Argon fill 44 mm
Light transmission value: 74.1%

Typical maximum sizes

Fixed light: 2500 mm X 2500 mm
Side hung: 950 mm X 1520 mm
Top hung: 1300 mm X 1650 mm

Please note: For Part Q and Secured By Design items,  there may be size restrictions. Please get in touch to discuss. 

Test results

Air Permeability BS EN 12207: 600 Pa Class 4

Water tightness BS EN 12208: 750 Pa Class E750 (Top hung)

Water tightness BS EN 12208: 900 Pa Class E900 (Side hung)

Wind load BS  EN 12210: 2400 Pa Class E2400

Exposure category BS 6375-1: 2400

* U values calculated for standard single window 1230 X 1480

Please see some sample styles below. If you can’t see the style you’re looking for, please get in touch, as everything we do is bespoke and made to your requirements.

Please fill in the quick form below to download a copy of the product specification clause:

Affiliations & Accreditations