The existing house that we were asked to look at extending and refurbishing was a very small single storey infill extension set between a large Victorian villa that had been converted into flats in the 1980s and a much larger 1950s office building that now houses a primary school. We had to retain the walls to the front and rear, and with the blank walls of the adjacent buildings forming the other two sides of the site, the only option was to extend upwards.

The new vertical ‘extension’ brings the living accommodation two storeys above the original single storey building. We have separated the front elevation of our building from the villa by inserting a small terrace at first floor level, which helps to retain the elegant symmetry of our neighbour and gives our clients valuable outdoor amenity space. To the front, the new façade rises from behind the existing brick wall in a dark grey render, a more recessive material than the existing brick at ground floor level. The new fenestration references the windows of the villa adjacent. At the rear, the rendered elements above the brick walls are of a looser composition, a random stacking of the spaces that leaves a more fractured but less austere elevation to the courtyard of the mews behind. Inside is a ground floor consisting of a dining room and a large kitchen with an old fashioned larder that is naturally ventilated to an undercroft bike store. Upstairs are two bedrooms and two bathrooms, a study area and a double height living space. The living space has full height glazing and sliding doors onto the aforementioned terrace, a library wall and is crowned with a rooflight that mimics a ‘James Turrell Skyspace’. This is where the structural fabric of the ceiling looks as if it is paper thin and appears to have hole in it that opens directly to the sky.

• YEAR: 2017 onward
• LOCATION: London