Angel Building, London - re-use of concrete frame

The re-use of an office building retaining the original concrete frame with new extensions using fair-faced concrete.

Located on the corner of St John Street and Pentonville Road, Islington, London, the five-storey office building has shed its tired 1980s facade and taken on a new modernist look.

Internally, much of the existing reinforced concrete frame has been retained. This means that the overall embodied energy of the building is substantially less than if it had been demolished and a new structural frame built. It also costs considerably less.

New extensions provide a new external facade and form a large atrium. The exposed concrete mass of the structure is used for passive cooling in conjunction with a displacement ventilation system. Throughout the building the exposed concrete is of a very high quality finish and the mix contains a 40 per cent fly ash replacement, which adds to the building’s sustainability credentials.

The retained concrete frame is wrapped with a highly-efficient glazed skin. The bespoke curtain walling works together with the exposed thermal mass of the concrete to passively control the internal environment and has contributed to the buildings ‘Excellent’ BREEAM rating.

Project team:

Client: Derwent London
Architect: Allford Hall Monaghan Morris
Structural engineer: Adams Kara Taylor
Main contractor: BAM Construction
Concrete contractor: Getjar Limited