Britannia Building Society, UK.

This project infills the existing courtyard at the Britannia Building Society Head Quarters with an ETFE roof to create a restaurant and staff relaxation area.

The existing building is a 1960s two-storey concrete frame on four sides of the courtyard, with an uninspiring precast concrete panel cladding.

The new roof to the courtyard is supported on steel tubular arches of varying radii and four steel tree columns. This structural form concentrates the roof loads onto four new foundation bases and minimises the additional load on the existing structure. Electrically operating vents are provided around the perimeter of the roof to control ventilation and smoke venting.

The new roof provides a light and airy space that contrasts the introverted nature of the original building.