ALUK Casement Windows

ALUK Aluminium Casement Windows Hertfordshire

Embrace the sophistication of steel coupled with the benefits of aluminium with Herts Glass. Ideal for homeowners, our 58BW ST HI aluminium windows are crafted with the highest standards in mind, making them an excellent replacement for existing steel windows. These windows not only exhibit exceptional thermal and acoustic performance but also mirror the slim sightlines typical of steel windows, all the while ensuring superior performance and heightened security.

Our commitment to quality is reflected in each installation being registered with Certass, the industry’s trusted governing body. By choosing Herts Glass, you opt for peace of mind and long-lasting performance, because your home deserves the very best. Contact us today for a free quote!


58mm or 70mm frame depth to accommodate varying types of applications
Double and Triple Glazing available
Available in a range of single or dual colour and anodised finishes
Certified under the Secured By Design scheme
Tested to PAS 24
Green guide rated A

U-Value (Double Glazing) (Ug: 1.0 W/m2K) 1.5 W/m²K

Window Energy Rating (WER) B-C
Air Permeability Class 4 (600 Pa)
Water Tightness Class 9a (600 Pa)
Wind Resistance Class E2400 (2400 Pa)
Acoustic Performance Rw (C;Ctr) 42 (-1;-5) dB
Unique polyamide thermal break design to improve thermal performance

Sightline (Frame to Vent) 66mm
Sightline (Vent to Mullion) 81mm
Sightline (Fixed Light) 43mm

Add some sophistication to your home

The aluminium windows by Herts Glass, styled to resemble steel, are the ultimate solution for steel replacements, delivering a slender, luxurious profile that emanates a sleek aesthetic. Leveraging inventive design and superior craftsmanship, these windows ensure optimal insulation, acoustic performance, and inherent robustness.

The ALUK 58BW ST HI window system we offer incorporates a versatile selection of profiles that can be tailored to either traditional sculptured or modern flat-line windows, making them suitable for any property type. Our windows are entirely pre-fabricated and assembled with all hardware installed and beads cut to precision.

Specialising in steel window replacements, we provide this high-performance aluminium window solution with five vent sections to ensure a faithful reproduction of the original steel frames. Our aluminium windows deliver heightened security, a broad colour palette, and impressive thermal benefits.