Windows set in a stone facade

The building's south facade faces a narrow city street. To reflect its smaller scale, the facade is divided into smaller elements - single windows set in the limestone wall and 750mm-deep recessed bays at fourth- floor level containing pairs of windows. They are surmounted by a band of horizontal aluminium louvres which act as a 'cornice', a visual stop which obscures the view of the storeys above. The use of material is restrained - golden-yellow stone slabs, structurally-glazed windows and black anodised aluminium metalwork.

The building, nine storeys high plus rooftop plant rooms, has post-tensioned concrete slab floors supported by a series of 1200mm-wide concrete columns set at 6m centres on the perimeter. The columns, used alternately with 1200mm-wide precast columns, form the internal skin of the facade between window openings.

French Lussac limestone slabs, 75mm thick with 6mm joints, were hand- fixed with a 75mm cavity, 50mm insulation and dpm to the internal skin; they are held at each floor level by support angles. Expansion joints - a 30mm recessed joint with 15mm silicone joint - are expressed at floor levels and at the centre-lines of the windows.

The 3m x 1.5m rectangular windows, with black anodised aluminium window frames, are a modern interpretation of the Georgian window. Their structurally- glazed faces are in the same plane as the stone, with a deep 150mm shadow gap around each of the two vertical sides. L-shaped stone slabs at each side of the window head appear to support a window 'brow', a 250 x 80mm black anodised aluminium coping which is clipped on to the head of the frame and projects beyond it.