PRECAST CLADDING TO A CONCRETE FRAME STRUCTURE
The building, housing production studios and offices, is a five -storey concrete frame structure with a sixth storey set back behind a parapet. The street facade facing Hoxton Square (shown right) is the resolution of two seemingly contradictory ideas. As the architect explained, 'We wanted to express the concrete frame and fill the voids with glass, yet create a monolithic brick building which would reflect its local surroundings.'
The resulting facade is a system of precast columns and beams faced with brickwork, reflecting the form of the concrete frame behind. They are structurally independent of each other. The facade - resting on the first- floor slab - requires only lateral restraint at upper levels, avoiding unsightly movement joints.
The columns and beams, made by Histon Concrete, are faced with Baggeridge blue engineering bricks, split in half to key the low-absorbency brick into the precast. The first row of columns was erected on site and tied back to slotted brackets, bolted to fixing channels cast in the floor slab. The precast concrete beams were then aligned to the column heads. The beams have support brackets cast into their ends, fixed to bearing plates at the heads of the precast columns. The next row of columns was then lowered. Each column has a pair of precast dowels, slotted into holes in the lower column. The joint was stitched with concrete and faced with two courses of brickwork to allow for inaccuracies. The backs of the columns were drylined and insulated.
As the facade and structure move independently, the glazing system was fixed to the facade. It comprises inward opening glazed doors and fixed lights of Crittall Corporate 2000 steel double-glazed units. The sills are of pressed aluminium.