KPG House is a single-storey building standing on the roof of a stone-clad apartment block overlooking Kensington Palace Gardens. Situated in a conservation area, the house’s exterior had to be designed as a sympathetic extension to the earlier structure, and it is for this reason that the steel frame of the new house is contained within the depth of the new construction. The main elevations are fully glazed, but nonetheless the construction of the roof includes a series of rooflights whose scale and cross section are closely related to the spaces they serve.
The house establishes a distinction between the different floors on a horizontal basis by separating the more public spaces, which are lined with limestone, from the private areas, which are lined with various kinds of timber. In the middle, there is a transitional zone that is occupied by the butler’s bedroom and the library: these spaces have stone floors and timber-lined walls. The west elevation is glazed using a system called Privalite; it forms a continuous wall and can be changed from translucent to transparent, by throwing a switch, when an electrical current passes through the gas contained in the void between the inner and outer faces of each panel. In contrast, the east elevation employs a system of folding and sliding glazed panels. Opposite the reception and dining spaces, they open onto a roof terrace where a steel arch supports a retractable canopy. When the canopy is not in use, the arch frames the view in this direction.