working details - One Knightsbridge Green Hurley, Robertson and Associates
A 1950s tower on a two-storey podium has been refurbished.
The street frontage has been lined with a row of two-storey retail units and a new main entrance; the podium roof has been made into a garden.
Each retail unit is a glazed bay, two-storeys high and 5.67m-wide with glass sliding doors. The bays are flanked at the top and sides with large terracotta tiles.
The original ground floor edge beam could not support the additional loads of the new shopfront glazing and cladding. Instead, each shopfront is fixed to a structural framework - a pair of horizontal trusses and steelcored window mullions - which is suspended from the second floor downstand beam. Three stainless steel brackets, bolted to the underside of the beam, are connected by steel rods and forked connectors to the upper truss. This in turn is connected by steel cored mullions and with a central suspension rod located within the vertical silicone joint between the two upper sheets of glazing, to the lower truss.The design allows the structure to deflect under the weight of the shopfront and for the dead load of the roof garden finishes.
Canted tubular struts, fixed at mid-height and at truss positions, stabilise the shopfront and transfer wind loads to 180 x 60mm wind posts and to the slab.The lower part of the shopfront rests on the ground floor edge beam with a horizontal movement joint between.
The glazed shopfront is weathered against the structural frame with EPDM bonded to the concrete, supported and protected by aluminium closure pieces.
The terracotta tiles act as a rainscreen and are fixed to aluminium cladding rails bolted to the concrete slab.