August 22, 2019

How to create an Opening Window in Structural Glass

Written by Rebecca Clayton

Invisio_floating_window (19a)
Structural glass walls are a favourite architectural glazing solution for architects looking to create a minimal design. The fixings of structural glass panels are hidden by the building finishes which creates an all-glass design.

How do you incorporate an opening window into structural glass?

As structural glass is fixed if an architect wants ventilation or opening elements into a structural glass wall, careful consideration needs to be taken to ensure that resulting design is in keeping with the intent. Below are three of the best solutions available for architects who want to incorporate an opening window into a structural glass window;

Invisio Floating Window

The Invisio 'Floating Window'

This is a unique solution to IQ which allows an opening aluminium window to be integrated into a structural glass window. By using high specification glazing units with specialist strengthening interlayers we can fix an aluminium casement window into the middle of a structural glass unit without any additional steel or support needed.

The opening window can be integrated into either top corner of the structural glass window or into the centre. The opening window is fixed securely into the structural glazing using a combination of mechanical fixings and structural bonding.

This solution maintains the minimal design of structural glazing whilst integrating an opening.

Floating Structural Window


Invisio Structural Glazing with Integrated Window

casement window with structural glass overhead. Water End House, Hertfordshire, 2017. Architect: Kirkland Fraser Moor.

For clients looking to reduce the costs of their opening window in a window, we can use slim steel sections to create an opening within structural glass for an opening window.

By using steel or timber supports within the structural glazing assembly we can reduce the specification of the glazing and provide a cost reduction to the client. The size of the supports required will depend on the size of the associated glazing, wind loads and glass weights.

A typical single-storey supporting structure will measure around 66mm wide. The overall sightline will then be the support plus the glass fixing and frame on either side of the support. This will depend on the systems being used. When using the Invisio structural glazing system with a Sieger Slim Casement the overall vertical profile would be approximately 150mm.


An Engineered Aluminium Casement

To create a large window with an opening vent within it, we can create a bespoke aluminium casement window assembly. The outer fixing of the window will be made from an aluminium casement window section which won’t be frameless like structural glazing but can be very minimal.

Beechcroft aluminium casement window arrangements Beechcroft aluminium casement window arrangements

Aluminium window arrangement to a bedroom at Beechcroft. Aluminium window arrangement to a bedroom at Beechcroft.

The intersection between the fixed and the opening window will then be a slim aluminium window frame. This will be more minimal than a steel support connection between structural glazing and an aluminium casement window.

This type of window arrangement can also be used in conjunction with a frameless glass to glass corner on the return, with the fixed aluminium window frame continuing around the corner at the head and the base.

Each of these three window options will fall into a different price bracket with the Invisio Floating Window the most expensive and the aluminium casement arrangement the more cost-effective.

The team at IQ are experts in our architectural glazing solutions and are on hand to assist you with your specification. If you would like some advice regarding your glazing specification just contact the team at IQ. If you let them know your design intent and preferred budget they can offer solutions to suit.