[WORKING DETAIL 02.07.09] Dormer detail
Grover Close − The design for this project utilises the full volume of each building, locating flats in the attic space created by a mansard butterfly roof. Full-height dormer windows are used, opening out on to small, private external areas between the dormer cheeks.
Dormers are an extension of the brick elevation below; facing brickwork carries up the front and wraps around the cheeks. This works to suppress the height of each building, which was an important criteria for planning. The inside of each dormer is clad in timber, with a timber deck offering external space.
To create a brick envelope supported by the timber roof structure, a timber frame is strengthened with plywood and clad in a proprietary insulated brick slip system. The flat roofs have a bitumen membrane and small aluminium copings, with openings to drain rainwater back on to the main roof. The local bricks used on lower elevations were cut down to create slips. These bricks proved quite soft, so cutting down pistol slips for the corners was a challenge.
Top-floor flats inhabit the full depth of the eaves, with ceilings stretching up to the roof ridge. This gives an exceptional volume to small flats, and allows plenty of space for storage. The dormer construction is key to ensuring the fabric’s performance is continuous across complex junctions between roof and dormer.
Claire Lützow, project architect, Buschow Henley