Conjuring up the illusion of space, Belsize Park, London NW3

Client: Private
Photographer: Emanuelis Stasaitis
Engineer: Michael Chester and Partners
Solar Panel Specialist: SogoSolar

Awards: AJ Retrofit, finalist
GAGA Award, shortlisted
Don’t Move, Improve, longlisted

SPA has mopped up the oil from the 20th century and swept out the straw from the 19th to transform this mews building into two airy modern homes.

Retained are the garage doors, humble facade and charming features of this diminutive former stables and former garage but gone is the sense of enclosure. A new full height slice of sky has been carved out of the volume to bring light and air into the whole building.

The small footprint is matched by a small developmental impact, a new building has been reassembled from the old parts of the original building. The walls have been augmented with breathable insulation and the roof has been decked out with solar cells. The new rear extensions are timber-framed, fully-insulated and bright-zinc-clad – a memento to the building’s utilitarian past.

The two bright flats combine the calm tones of birch ply fitted joinery with the rawness of exposed brickwork and steelwork. Both flats enjoy private outdoors at the back of the house, adding to the graceful living within.

To top it all the energy efficiency rating is now an impressive 91% – an improvement of 40% on the old building’s rating which is sure to keep the bills low.