Private house roof extension in Brockley, London - Phase 1(2024)
The project involves two properties on Manor Avenue in the London Borough of Lewisham; they are post war Modernist style 2 storey terrace dwelling houses with a basement, built as a pair on a bomb site between two remaining Victorian houses built c.1860. The Victorian dwelling houses on Manor Avenue generally consist of short terrace blocks of four dwellings with the outer ones featuring hipped roofs, which, together with the deep overhanging eaves, gives visual coherence to each group.
The roof extension design adds a flat roofed single storey volume, set back from the front face of the original building line. As the new floor level will start at attic floor level about half of its volume is concealed behind the existing brick parapet of the front elevation..
As only one roof extension was to be built the issue of compositional balance arose and therefore, in mitigation, a beam and column structure was added extending over the roofs of both houses to ensure compositional balance. The beam structure continues the roof eaves lines of the two flanking Victorian properties, thus maintaining continuity and balance, and protecting the character of the two properties as a group and the street as a whole. The beam structure evokes the appearance of a roof garden an seen on many Modernist houses of the 1930s by Terragni, le Corbusier and others.
To create a well functioning transition from the existing first floor to the new top floor the design converts the front box room into a lobby and library/reading area, from which the staircase rises to the new studio space on the roof. This allows fire separation of the upper floor to be achieved with a concealed fire door integrated in a storage cupboard and bookshelving. Ash flooring is used for the library/ lobby, the new stair and the studio space. The extension roof structure leaves the timber joists exposed with special fixings used to avoid the need for unsightly timber blocking in the plane of the exposed roof structure.
