Structural Design and High-Performance Glazing
IQ Glass delivered a complete architectural glazing package designed to fulfil both the visual and structural ambitions of the project. The glass box extension was formed using large-format structural glazing panels with minimal framing, allowing uninterrupted views and maximum daylight penetration throughout the space.
Carefully engineered glass assemblies enable multiple elevations to appear frameless, with structural silicone joints and precision installation methods ensuring clean, flush finishes. These details are critical in glass box extensions, where even the smallest inconsistencies can impact the overall aesthetic and visual clarity.
The glazing systems were seamlessly integrated with the building structure, incorporating concealed support elements where required. This design ensures the extension achieves its desired minimal appearance while remaining fully compliant with structural performance requirements.
Alongside the visual design, high-performance glazing was specified to ensure the extension performs as a comfortable, year-round living space. Thermally efficient glazing units with low-emissivity coatings reduce heat loss, while solar control glass helps regulate internal temperatures and minimise overheating in highly glazed areas.
Where necessary, discreet opening elements were incorporated into the glazing design to provide natural ventilation without interrupting the clean lines of the structure. The result is a refined glass extension that balances aesthetic precision with practical, year-round functionality.
Technical Specification: Glass Box Extension Systems
IQ Glass provided a full glazing package for Collingwood, including slim sliding doors, Invisio structural glazing and bespoke glass beams.
Glass box extension formed using slim framed sliding doors and frameless structural glazing to create a minimal glass enclosure
- Two sets of slim framed sliding glass doors create the walls of the glass extension.
- Front elevation two track, four panel slim slider in a bi‑parting configuration, measuring approximately 9.4m wide x 2.6m tall.
- Side elevation two track, two panel sliding door system with one fixed pane and one sliding panel, measuring approximately 2.7m wide x 2.6m tall.
- Frameless structural glass roof to the glass extension measuring 9.5m wide x 4.6m deep with 5° fall, made from 4 structural glass panes with silicone joints supported by glass beams.
- Stepped front edge detail creating 44mm drip edge overhang
- Notched to integrate with existing building structure
- Double glazed with 10mm toughened outer pane and laminated 2 x 6mm inner pane
- Solar control coating achieving ~70% light transmission and g-value of 0.35
- Structural glass beams constructed from multiple layers of laminated low iron glass and designed with integrated channels for concealed LED lighting
- Structural steel beam above sliding doors clad with 3mm bespoke insulated aluminium pressings
- Shaped structural glazing to infill junction between roof and side elevation measuring approximately 2.8m wide x 0.4m high at peak
- All glazing units heat soak tested
- Entire structure engineered to withstand wind loads of approximately 0.9 kN/m²
- All aluminium framing and pressings finished in PPC RAL 7016
Speak to IQ Glass About Your Glass Box Extension
Speak to our team about delivering a high-performance glass box extension or architectural glazing project in Tunbridge Wells. We specialise in high-end residential glazing, offering minimal framed designs that combine advanced performance with precision detailing.
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