‘My first thought was to have the whole thing be a swimming pool’: the basement refurb that optimised space to the max

A curved staircase leads down to the basement lounge. Shelves and dining table are by Shaw; B4 stacking dining chairs are by Börge Lindau for Blå Station. All photographs: Mark C O’Flaherty/The Guardian Photograph: Mark C O'Flaherty/The Guardian

Excavation in modern architecture has a bad rap these day, but when furniture designer James Shaw bought a mini plot of land close to Columbia Road flower market in east London, he realised he would have to build down if he wanted to turn it into a home.

The result, developed with architect Nicholas Ashby, is an extension of James’s experimental, colourful product design – and an example of how to make even the most awkwardly sized plot stylish.