The VS-1 curtain walling system from FGS was specified for the ‘Believe in Better’ Building due to its ability to easily span large heights with clean, unbroken sightlines.
BREEAM ‘Excellent’ rated, the 3,000m2 timber framed building is designed in-line with Sky’s sustainability strategy throughout, with a thermally superior fabric, photovoltaic (PV) electricity generation and rainwater harvesting just some of the integrated measures.
FGS was tasked with the £3m project to detail design, manufacture and install the whole building facade. The key feature of this is a centrepiece ground to fourth storey staircase which Arup hoped would offer building users uncluttered views across the adjacent and newer parts of the Sky complex.
The suitability of VS-1 was immediately apparent. As a mullion-only system which requires no mid-point horizontal structural support for very large spans – 12.5m in this case – and no transoms, VS-1 met the architects’ vision and ensured Sky could realise its ambition to match eye-catching aesthetics with an open internal environment benefitting from plenty of natural light.
The Believe in Better Building features externally mounted VS-1 mullions which have a distinctive ‘aerofoil’ shape to support the glazing along the full length of the 51m staircase, over which it rises some 15m. These are highly engineered aluminium extrusions which are secured using stainless steel brackets at top and bottom cantilevers from the building’s timber structure. These ensure a secure attachment at the top of the structure and at each floor level.
VS-1’s brackets hold the glass panels away from the mullion to give it a ‘floating’ effect – these are then siliconed at the top and bottom to give a flush finish. Each double glazed sealed unit – many of which are 3.2m high – features 13.5mm SGG Planidur heat strengthened, laminated panes of glass on the interior and 8mm Securit toughened, heat soak tested on the exterior. The glass is Saint- Gobain’s COOL-LITE SKN165 II which was chosen to balance solar control and thermal insulation.
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