Glass Extension in Sussex | Bosham Project by IQ Glass

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Bosham is a house refurbishment and glass extension in Sussex near Chichester, designed by Smith Simmons & Partners with photography by Julia Toms Photography. IQ Glass supplied a coordinated architectural glazing package for the contemporary rear extension, including slim framed sliding glass doors, fixed frameless windows, roof terrace glass balustrades and solar control glass.

The ground floor glazing includes minimal sliding doors in slim, dark-toned aluminium frames, with multiple configurations and a specialist glass-to-glass corner connection. Marine-grade glazing materials were specified as part of the glazing package due to the coastal setting.

Products Used

Project Partners

Architect: Smith Simmons & Partners

Photography: Julia Toms Photography

Location

Chichester, Sussex

Glass extension in Sussex - Bosham - IQ Glass

Glass extension in Sussex for a traditional coastal property

The project required contemporary structural glazing to be integrated into a traditional coastal property with flint masonry and a clay-tile roof. The design challenge was to introduce large openings, improved transparency and stronger garden connections without allowing the glazing to dominate the existing building fabric.

This glass extension in Sussex uses slim aluminium framing, concealed structural glazing frameworks and glass-to-glass junctions to reduce visible mass at key interfaces. The glazing sits alongside the texture of the flint masonry and the weight of the traditional roof form, creating a clear contrast between old and new while keeping the overall composition controlled.

The ground floor openings needed to bring more daylight into the refurbished internal spaces and improve the visual connection to the landscaped exterior. At the same time, the glazing had to respond to site exposure, coastal proximity and the need for clean junctions between contemporary glazing systems and traditional construction.

Rather than treating the glazed extension as a separate visual feature, the specification uses each glazing element to solve a defined architectural condition, including wide openings, corner transparency, fixed frameless glazing, roof terrace guarding and solar performance.

Multi-panel sliding doors with a glass-to-glass corner

The ground floor extension is centred around ultra-slim sliding glass doors in multiple complex configurations. The slim, dark-toned aluminium frames were selected to keep the visible framing low while supporting large glazed openings to the rear of the property.

A specialist glass-to-glass corner connection was used at the corner condition, allowing the sliding door arrangement to maintain transparency where a heavier framed junction would have interrupted the view. This detail supports the open relationship between the internal living spaces and the landscaped garden.

The sliding door system addresses several design requirements at once. It increases daylight, creates flexible access to the exterior and keeps the architectural language of the extension deliberately minimal. The low sightlines also help the contemporary glazing sit more quietly against the traditional material palette.

Fixed frameless windows and roof terrace balustrades

Structural glazing systems were integrated as fixed frameless windows within the extension. These fixed units include glass-to-glass corner connections and concealed frameworks, allowing the glazing to form clean junctions without the visual interruption of conventional window framing.

Above the ground floor, frameless structural glass balustrades enclose the accessible roof terrace. The balustrade run spans 15 metres, providing guarding around the terrace while preserving outward views.

This was an important balance for the upper level. The roof terrace required a safety barrier, but the architectural intent depended on maintaining open sightlines and avoiding heavy visual elements above the traditional clay-tile roof and flint masonry. The frameless glass balustrades provide the required guarding while keeping the terrace edge visually light.

Performance considerations

Performance was a central part of the glazing specification for this glass extension in Sussex due to its coastal location and increased glazed area. All glazing was specified with solar control coatings to help manage solar gain and support internal comfort across the enlarged glazed areas.

Marine-grade glazing materials were specified throughout the glazing package in response to the coastal proximity. This supports long-term durability in a setting where exposure to moisture, wind and airborne salts can place additional demands on external building elements.

The fixed frameless windows use concealed frameworks to maintain a minimal appearance while supporting the required structural and thermal performance. The glass-to-glass corner connections reduce visible framing at key junctions, but also require careful coordination with surrounding structure, fixing positions, tolerances and weathering details.

The sliding door package was selected to provide large openings while retaining tested performance for air permeability, driving rain and wind resistance. Across the project, the glazing specification brings together daylight, views, thermal control, coastal durability and clean detailing without overstating the role of any single product.

Technical details

Slim framed sliding doors: 21mm sightline; glass thickness 26 to 32mm; max tested sliding pane 8.5m² up to 4.0m high and 500kg; typical Uw > 1.1 W/m²K; Air Class 4 / Driving rain Class 7A / Wind Class C4/B5; PAS 24 security. Project includes multi-track sliding door configurations with a specialist corner connection.
Fixed frameless windows / structural glazing: thermally broken fixing profile depth 63mm; max glass thickness 41.5mm; expected Uw 1.1 W/m²K; minimum fixing setback 55mm; structure deflection allowance 5mm. Used for fixed frameless glazing and glass-to-glass corner connections within the extension.
Frameless glass balustrades: toughened laminated glass up to 21.5mm; max height 1100mm; line load up to 3kN; max pane width 6000mm, project-calculated. On this project, a continuous 15m run encloses the roof terrace while preserving coastal views.
Coastal glazing specification: solar control coatings applied across the glazing; marine-grade glazing materials specified to support long-term durability in the coastal setting.

Bosham shows how a glass extension in Sussex can balance contemporary architectural glazing with traditional flint masonry and clay-tile construction in a coastal setting.

This approach is suited to refurbishment and extension projects where slim sliding doors, fixed frameless windows, glass-to-glass corners, roof terrace balustrades and a marine-grade glazing specification need to work together as part of one coordinated package.

To discuss a similar glass extension in Sussex, architects and specifiers can contact IQ Glass for technical advice on product selection, interface detailing and coastal glazing performance.

Associated Products

luxury new build home with minimal glass facade

Slim Framed Sliding Glass Doors

Sliding doors with ultra-slim sightlines, offering only the highest levels of performance and durability.

Solar Control Glass

Solar control glass is used in buildings to reduce heat gain and glare from the sun. It can also help to conserve energy and improve occupant comfort and productivity.