Alongside the remaining large Victorian villas, there are numerous speculatively-developed, mid-rise mansion blocks and apartment buildings in North London. High London is typical: a six-storey block of heavy masonry, built in the 1960s at the summit of Hornsey Lane. Our clients asked us to find ways of improving – and ideally, extending it. Consulting with the structural engineers, we knew that a single storey could be added on top of the existing structure, but after closer inspection, we saw that by removing one storey we could actually put three back, using a lighter weight steel frame construction with timber floors. The resulting eight floors would match the height of the neighbouring buildings, effectively filling in a missing tooth on the street.

Externally, we are giving the existing building a facelift and improving the thermal performance by replacing the windows and spandrel panels.  The three storey extension is clad in coloured fibre cement panels to complement the unusual pink concrete bricks of the existing building that change colour depending on the quality of the light. A metal portal creates a distinct entrance and compliments the delicate perforated balconies to the rear.

Inside the building, we have created a more rational layout of the two-bedroom apartments to optimise the opportunities for space and light.