CASE STUDY
Cross Street
Products used
Structural Glazing; Aluminium Windows; Aluminium Casement Doors; Corner Windows
Location
Padstow, Cornwall
Project Overview
Glass-to-glass corner glazing in Padstow defines Cross Street, a two-storey contemporary rear extension within Padstow Conservation Area. Designed by Angus Webster Architects, the project uses fixed structural glass returning through an internal corner at both ground and first-floor level, creating a minimal glazed elevation without a conventional corner mullion.
The original glazing package was delivered by IQ Glass and combines structural glazing with a top-hung aluminium window and outward-opening aluminium casement door. Marine-grade finishes were specified for the coastal location, with the complete elevation coordinated around the floor slab, steelwork and surrounding building interfaces.
Interior and lighting design was by Millard & Flo, with photography by Billy Bolton Photography.
Project Challenges
Glass-to-glass corner glazing around a two-storey slab line
The principal challenge was to create a continuous glazed corner across two storeys while accommodating the floor slab and structural steelwork between them. The fixed glass needed to remain visually dominant, with the structural division kept behind the glazed plane rather than expressed as a heavy external frame.
The conservation area setting also required the rear extension to read as a controlled contemporary intervention. Minimal framing and a transparent corner were therefore central to the architectural approach.
Opening elements created an additional coordination issue. An inward-opening door at ground floor would have conflicted with the slab arrangement, while ventilation was still required at first-floor level.
Project Solutions
Structural glass returns with separate aluminium openings
Fixed structural glazing forms the corner at both levels, with the panes meeting through a structural silicone joint rather than an aluminium corner mullion. Concealed perimeter profiles allow the glazed returns to maintain a frameless effect while providing the required structural and thermal support.
At ground floor, an outward-opening aluminium casement door was specified to avoid interference with the floor slab. A head-fixed restrictor controls the door movement, while the adjacent first-floor opening uses a top-hung aluminium window for ventilation.
Keeping the moving elements beside the structural glass rather than within the corner allows the glass-to-glass junction to remain visually uninterrupted.
The visible aluminium framing, handles and perimeter pressings were finished in RAL 7044 Matt, with a marine-grade PPC specification selected for the exposed coastal location.
Project Highlight
The same glass-to-glass corner detail continues above and below the intermediate floor slab. By keeping the slab and steelwork behind the glazed plane, the two-storey elevation maintains a consistent frameless corner despite the structural division between floors.
End Result
Performance considerations
The glass-to-glass corner glazing in Padstow was designed to a confirmed project wind load of 800 Pa, with a maximum recorded individual glass weight of 182kg.
Thermally broken structural glazing profiles support the fixed glass, while the framed door and top-hung vent form part of the same insulated external envelope. Perimeter seals and aluminium pressings were coordinated where the glazing meets the slab, steelwork and surrounding construction.
Marine-grade PPC was specified for exposed aluminium components in response to the coastal location. The RAL 7044 Matt finish was continued across framing, pressings and door hardware to maintain a consistent appearance.
Restricted rear access also influenced installation. Glazing and associated metalwork were delivered by flatbed and sequenced around the constrained site conditions.
Sieger’s conclusion
Cross Street demonstrates how glass-to-glass corner glazing in Padstow can be coordinated across a two-storey extension without introducing a visually dominant corner post.
The combination of structural glazing, a top-hung window and an outward-opening casement door resolves daylight, ventilation and access while responding to the slab position, coastal exposure and conservation area context.
This approach is suited to architects and designers working on extensions where structural glass corners, aluminium openings and complex building interfaces need to operate as one coordinated elevation. Contact Sieger Systems for technical advice on structural glazing, aluminium casement doors, window configurations and marine-grade finishes.
Performance considerations
The glass-to-glass corner glazing in Padstow was designed to a confirmed project wind load of 800 Pa, with a maximum recorded individual glass weight of 182kg.
Thermally broken structural glazing profiles support the fixed glass, while the framed door and top-hung vent form part of the same insulated external envelope. Perimeter seals and aluminium pressings were coordinated where the glazing meets the slab, steelwork and surrounding construction.
Marine-grade PPC was specified for exposed aluminium components in response to the coastal location. The RAL 7044 Matt finish was continued across framing, pressings and door hardware to maintain a consistent appearance.
Restricted rear access also influenced installation. Glazing and associated metalwork were delivered by flatbed and sequenced around the constrained site conditions.
Sieger’s conclusion
Cross Street demonstrates how glass-to-glass corner glazing in Padstow can be coordinated across a two-storey extension without introducing a visually dominant corner post.
The combination of structural glazing, a top-hung window and an outward-opening casement door resolves daylight, ventilation and access while responding to the slab position, coastal exposure and conservation area context.
This approach is suited to architects and designers working on extensions where structural glass corners, aluminium openings and complex building interfaces need to operate as one coordinated elevation. Contact Sieger Systems for technical advice on structural glazing, aluminium casement doors, window configurations and marine-grade finishes.
Glass-to-glass corner maintained across ground and first-floor glazing
Floor slab and steelwork retained behind the glazed plane
Outward-opening door and top-hung vent preserve the fixed corner detail
Marine-grade RAL 7044 Matt finish specified for the coastal location
Technical specifications
| Structural Glazing | Thermally broken structural glazing with a 63mm fixing profile depth, maximum glass thickness of 41.5mm, expected Uw 1.1 W/m²K, minimum fixing setback of 55mm and structure deflection allowance of 5mm. |
| Glass-to-Glass Corner | Fixed structural glass returns at ground and first-floor level connected through structural silicone joints, removing the requirement for an aluminium corner mullion. |
| Aluminium Casement Door | Ground-floor outward-opening aluminium casement door with a head-fixed restrictor. The outward-opening configuration prevents interference with the intermediate slab. |
| Top-Hung Aluminium Window | First-floor top-hung opening positioned beside the fixed structural glazing to provide controlled ventilation without disrupting the corner junction. |
| Project Structural Requirements | Confirmed design wind load of 800 Pa and maximum recorded glass weight of 182kg. |
| Frame and Hardware Finish | Marine-grade PPC finish in RAL 7044 Matt, with PPC door handles coordinated with the surrounding aluminium framing. |
| Perimeter Detailing | Aluminium pressings and seals coordinated around the structural glazing, slab, steelwork and adjacent building fabric. |
| Product confirmation required | The exact aluminium window model should be confirmed before adding verified sightlines, maximum sizes and air, water and wind classifications for the opening vent. |
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