York Townhouse

Floating Structural Glass Extension in North Yorkshire

At Sieger Systems, we believe in transforming spaces through structural glass extensions that blend aesthetics with functionality. Collaborating with Mass Architecture, we reimagined a period townhouse in York by creating a ‘floating’ industrial-style glazed extension that maximises natural light and enhances the connection between the home and its garden.

The client owned a narrow four-story terrace property, constrained by its period design and limited footprint. An existing external metal terrace was underutilised and didn’t align with the client’s vision of a bright, open space. Our challenge was to introduce a structural glass extension sunroom that would flood the interior with natural light without casting the lower ground level into shade, all while respecting the property’s historical context.

To achieve this, we supplied a range of our premium products, including Invisio Structural Glazing, and the Sieger 120 Bifolding Door System. Sieger Systems also supplied a 1871mm x 3298mm single casement door with a sidelight and toplight, a 4876mm x 2200mm casement window with 8 fixed panels and 4 top-hung panels, and bifolding doors in configurations of 2157mm x 2150mm (3 panes) and 1365mm x 2150mm (2 panes). These products were chosen for their slim profiles and ability to maximise glass area, enhancing the intake of natural light into this structural glass extension.

Our team implemented innovative design solutions that included frameless effect fixed glass roofs with silicone-jointed panes supported by steel sections. This allowed light to penetrate deep into the interior spaces. The Sieger 120 bifolding doors, with their slim profiles, created wide opening apertures, blurring the lines between indoor and outdoor areas. These full height bi folding doors were finished in Anthracite (RAL 7016), colour coordinated with the structural steel foundations. We also incorporated etched, slip-resistant walk-on structural glass floor panels above the existing boiler room, allowing light to cascade into the lower levels.

Technical enhancements such as solar control coatings were applied to the structural glass to prevent overheating during the summer months. Additionally, a rain chain was integrated to effectively drain water from the Invisio glass roof, complementing the industrial aesthetic.