Green Park is a 180 acre business park with access from the A33 off junction 11 of the M4. The site has permission for 2.25m sq ft of predominantly business space divided amongst 14 plots, each with its own access to the Park’s road network. 500 Brook Drive consists of 13,285 sq m (143,000 sq ft) of office accommodation over five storeys. The building has a bold sculpted shape that wraps around a full height central atrium. At ground and first floor, two parallel wings are joined by the entrance hall to a split service core. Three further floors form a ‘U’ shaped single space that wraps around the entrance hall. Cantilevered bridges are the primary means of access from the atrium to the office space at the upper levels which are served by a triple lift core. The entrance is a cube centred within the full height glazed façade, shaded by the oversailing roof and flanked by two opaque glass-clad stair towers. Further staircases form external sculptural features. These are unique in their integral structural support, using an inner string cut from a single steel tube which takes the form of a helix ribbon. Additional bracing is provided in the connecting floor landings which help counter the torsional forces. A BREEAM ‘Excellent’ rating is achieved with displacement floor ventilation and chilled beams which greatly enhance the occupier’s working environment.