Optio 58BW HI Casement Window


Why Choose Our AluK 58BW HI Windows?

Versatile and energy-efficient with plentiful options for configurations and styles, this modern-day classic will transform your home. The 58BW HI Casement window system is built to the highest UK standards, ensuring the highest levels of safety and performance to keep your home warm and secure.

Four Different Aesthetics

The clean lines of this highly popular casement window range can be further enhanced with four different aesthetics to suit your property. Whether you're looking for the slim and stylish stepped edge of ovolo designs or the traditional chamfered design to compliment your heritage style property, we have designs for all tastes and preferences.

In comparison, our square designs offer a modern and minimal flat sash for contemporary designs, and our flush casement windows provide slim sightlines to meet the popular flush aesthetic. With a range of customisable options, including slim and standard frame depths, the 58BW HI window is the perfect choice for both traditional and contemporary residential designs.


Low U-values of 1.2 for triple glazing and 1.4 for double glazing, B-C WER (Window Energy Rating), and a Green Guide ‘A’ Rating make this energy-efficient window the ideal partner for both new build and refurbishment projects where warmth and comfort are paramount.

With impressive air (Class 4 - 600Pa), water (Class 9A - 600Pa), and wind resistance test figures, this system can withstand extreme weather conditions, keeping your home warm and dry.

Technical performances

  Standard technical data HI technical data
U value W/m²K 1.2 W/m²K - 1.5 W/m²K 1.2 W/m²K -1.4 W/m²K
Window energy rating B-C B-C
Air Permeability Class 4 (600 Pa) Class 4 (600 Pa)
Water tightness (Pa) Class 9a (600 Pa) Class 9a (600 Pa)


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