AVCIARCHITECTS’s design for telecom giant BT Wholesale’s central offices in London transformed a former telephone exchange building into a model of the modern, open workplace. In addition to programming an open floorplan, the project added a new reception level, executive office floors, and a rooftop restaurant. The use of sub-industrial materials, such as backlit polycarbonate and cast glass panels, set against such rich traditional materials as walnut, adds a touch of industrial chic while maintaining a sense of corporate quality.