Passing this Victorian house in West Hampstead, there are few external clues to the changes within. There's that slightly scrubbed look that often follows building work; the ground floor windows have translucent film rather than curtains; and a few white planes are visible through upper windows.And though within a conservation area, at around 750m 2it is a rare example of a house here without multiple doorbells.
The owners used to live on the basement and ground floors - now they own the whole building. The reintegration of the house is marked by a new open core reaching from ground floor to roof. At the roof a large skylight spreads over this core, over the staircase to the edge of the building, yet is invisible from the street.
The approach of designer Bluebottle is minimal plus. The new core is all planes of plastered white, with clear glass balustrading. But the carpet is purple, a rich colour that shifts markedly as you move up from artificial light at lower level to daylight at the top. One wall is painted red, with a sheet of glass glued on top. Lime green pervades the bathroom.
On the upper floors the landing areas are generous. With continuous ceiling planes across each floor, uninterrupted by using wide floor-to-ceiling doors, the space flows freely between core and the surrounding refurbished, uncluttered rooms. Some have their double doors held open, feeling more like enormous alcoves than separate rooms.
The core defines everything.