Segal House extension, Highgate, London

A remodel and extension of two storey detached house in Highgate, North London, designed in the 1970’s by Walter Segal. A large timber extension slots between the side of the house stepping vertically and horizontally following the natural topography creating a continuous diagonal sequence of spaces and route through to the garden.

The design avoided the need for deep foundations thus the extension sits on a thin, stepped raft slab, which in turn floats on a layer of recycled glass granules. The glass replaces traditional hardcore and insulates the underside of the raft, eliminating the need for further floor insulation.

The extension superstructure was designed using glue laminated framing with cross laminated timber panel infills. Carefully integrated glulam transfer beams at 1st floor, together with a central glulam portal frame provided lateral stability, preserving the open plan spaces and stepping geometry and avoiding any interruptions from projecting columns and downstand beams.

Environmental Leadership Prize, “Don't Move, Improve!” Awards, 2021

Architect: Morris and Company and Johanna Molineu Architects