VELFAC composite windows bring together the best of both worlds; the durability and versatility of aluminium and the beauty and warmth of natural wood. Aluminium is both highly durable and low maintenance, ensuring the windows will last 40 years or more. The wood frame contributes to great energy performace with U-values as low as 0.8W/m2k . VELFAC 200 System aluminium/wood windows also deliver contemporary styling. The slim 54mm sightlines maximise natural light, and opening and fixed lights have the same sightlines, providing a consistent aesthetic across window units.