Optio 58BW ST HI Window

Black aluminium windows external view

Looking to replace and complement existing steel windows? The minimal, durable and secure 58BW ST HI window is designed for that


Designed to replace and complement existing steel windows, the range has been specifically developed for use on buildings where steel windows have traditionally been fitted. The 58BW ST HI profiles feature traditional square sections and sightlines of just 43mm in a fixed light.

The range is available in a wide range of standard and RAL colours. Anodised finishes are also available, with marine grade guarantees on request.


  • Slim sightlines to match existing steel windows.
  • Internally and externally beaded for ease of site glazing on high-rise applications.
  • Unique polyamide thermal break design to improve performance Integrated deep head profiles for ease of trickle ventilation.
  • Accommodates standard hardware including friction stays and shoot bolt locking.
  • Certified under the Secured By Design scheme.
  • Ideal for Heritage, Listed Buildings and steel window replacements.


  • Accommodates up to 32mm glazing units for thermal and acoustic performance.
  • Casement clips available for easy fit and removal of dummy vents.
  • Dedicated fixing straps for ease of installation.
  • Four different sash profiles to achieve design and planning permission requirements.
  • Available in single or dual colour polyester powder coating, texture and anodised finishes.


Available in a wide range of styles including Top Hung, Side Hung, Bottom Hung, Fixed Light and Multi Light, the system cleverly replicates the narrow sight lines associated with steel windows whilst providing superior performance and security.

The system also includes hardware that is sympathetic to traditional steel window designs.

The 58BW ST HI offers high thermal efficiency with U-values as low as 1.4 for double glazed and 1.1 for triple glazed, ensuring your home is warm and comfortable.

With excellent air, water and wind resistance test results, this system can withstand the worst of British weather.

And with full PAS 24 and Secured By Design accreditation, you can feel safe and secure with this superior system.

Standard Technical Data HI technical data
U value W/m²K 1.5 W/m²K 1.1 W/m²K -1.4 W/m²K
Air tightness (Pa) Class 4 (600 Pa) Class 4 (600 Pa)
Water tightness (Pa) Class 8A (450 Pa) Class E1500 (1500 Pa)
Wind load (Pa) Class E2400 (2400 Pa) Class E2400 (2400 Pa)

Delighted with the authentic look

“As with any owners of a listed property, finding the right company to take time to understand our requirements and provide a bespoke product and carefully tailored service was key. We considered other options, but the team at Tradeglaze have been terrific and their AluK Heritage windows, with an authentic look and excellent weather performance, were ideal for our property and for getting our planning permission approved. We are delighted, and the look and feel are exactly what we had hoped for.”

Harby Mill homeowners - November 20, 2020

Exactly what I was hoping for

“The finished look is exactly what I was hoping for. The house now has a modern, contemporary feel, which still respects its original design and character.”

Traditional semi-detached house owner - March 27, 2021