Sliding glass doors with steel look windows in South London were used to transform this rear extension from a small, cramped kitchen and dining area into a brighter family space with stronger garden connections. IQ Glass supplied and installed a coordinated glazing package combining a three-panel sliding glass door, steel look corner windows, a run of aluminium casement windows and colour-matched aluminium pressings. Together, these elements created a layered glazed elevation that increased daylight, opened the rear of the house and gave the extension a more resolved architectural identity.
Products Used
Project Partners
Granit Architects
Photography by Andrew Beasley
Location
South London
Sliding glass doors with steel look windows in South London for a layered rear elevation
The design challenge for this extension was not simply to add more glazing, but to make the rear elevation feel more open, textured and architecturally controlled. The architects wanted a stronger connection to the garden, but also a more layered material composition than a single run of glazing would have provided. Sliding glass doors with steel look windows in South London therefore became the central design response. A large sliding opening addresses access and openness to the garden, while the steel look corner window and adjoining aluminium glazing create a more articulated glazed composition. This allowed the rear of the house to feel lighter and more connected to the outside without losing definition, rhythm or ventilation control.
Sliding door and steel look corner window as one glazed opening
The main rear opening uses a three-panel sliding glass door to create the principal connection to the garden. By opening the majority of the rear elevation, the door solves the brief for a stronger inside-outside relationship while maintaining minimal framing across the largest opening. That sliding system connects directly to steel look windows which wrap around the corner of the extension, creating a more layered glazed edge than a single facade treatment. Because two different glazing systems had to meet at this point, aluminium pressings were used to merge the junction cleanly so the combined elevation reads as one continuous installation rather than as separate adjoining elements.
Side-return glazing, engineered plinth and integrated ventilation
A second challenge was to continue glazing along the side return without losing visual order or practical ventilation. To the front of the extension, a steel look slip window incorporates an opening vent at high level with fixed glazing beneath, mirroring the wider composition. This connects at 90 degrees to a run of thermally broken aluminium casement windows along the length of the kitchen extension. The entire glazed corner was installed onto an engineered brick plinth and positioned on the outer edge of that construction, which in turn created a deep internal cill that doubles as a window seat. At the end of the run, a side-hung opening vent is integrated into the composition so the extension can achieve additional airflow without breaking the overall glazing line. In this way, sliding glass doors with steel look windows in South London solve access, daylight and ventilation together rather than as separate design moves.
Performance considerations
This extension relies on careful coordination between several glazing systems rather than one large opening alone. The sliding door, steel look window and aluminium casement glazing all had to align visually while maintaining the thermal performance expected of a modern rear extension. Thermally broken framing was used to the aluminium window run, and the layered arrangement of opening elements allows the space to balance daylight, access and controlled ventilation. The connection details between the sliding door and the steel look windows were also critical, ensuring that sliding glass doors with steel look windows in South London remained visually clean, durable and coherent in day-to-day use.
Technical details
- Slim framed sliding glass doors: 20mm vertical junction; panes up to 2500mm W × 3000mm H (up to 320kg); Uw 1.3 W/m²K; tested to Air Class 4 / Water Class 7A / Wind Class C5; acoustic reduction up to 41dB; up to 4-point locking. On this project, a three-panel sliding configuration was used to open the main rear elevation.
- Steel look windows: sightlines 33mm fixed / 58mm casement / 76mm tilt + turn; glass thickness 24–28mm; Uw 1.5 W/m²K (calculated per project); Air Class 4 / Water Class 9A / Wind 2400 Pa; PAS 24. Here, the steel look slip window includes a top opening vent over fixed glazing.
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