A sensitive but substantial renovation of a C.H.B Quennell-designed villa, provides a contemporary space for a client with a challenging brief.
Located in a conservation area, a number of planning constraints were imposed on the scheme. The building’s appearance was to remain in keeping with its surroundings, and the masonry façade retained. To achieve the client’s desire for an increase in space, much of the renovation had to take place below the building with a new two-storey basement accommodating recreational facilities including a swimming pool, gymnasium and garden room.
The planning constraints were not the only challenge of the renovation. The location of the swimming pool in the middle of the basement area, and directly below the front of the existing building made supporting the masonry façade even more difficult.
To construct the basement, the façade was temporarily supported while the new supporting structure was installed below. To propose an efficient structural solution for the basement box both the construction sequence and temporary works were considered as they were integral to the scheme as a whole. The solution was to cast the ground floor slab through the masonry façade and on top of the bearing piles. The basement could then be excavated, leaving the bearing piles to support the façade until the permanent steel columns were installed.
While the basement was being excavated, the above ground works could progress unencumbered. The interiors and existing plan were opened up, window openings increased to improve daylight levels and connections between rooms were enlarged.
Despite the constraints imposed, the project realises an almost nine-fold increase in the property’s size.