Set within the Kew Green Conservation Area of south-west London, this four bedroom family house is formed of two prefabricated weathering steel volumes inserted behind a retained nineteenth century stable wall. The layout is informal; rich with incidental spaces, unexpected light sources and contrasting volumes. Split into two wings, the simple plan makes the most of a constrained site and responds to the living patterns of the young family. Piercy&Company created an internal landscape of alternative routes, levels, and spaces – many of which are aimed more at children than adults, such as the slide providing rapid access to the basement from the first floor. Manufactured in Hull and assembled on-site, the two shells housing each wing are formed of 4mm thick Corten steel - a hardworking combination of structure and façade. The rustic weathering steel exterior is maintenance free and softened by a patchwork of expressed welds and perforated panels. The deep orange tones and perforations within the skin echo the dappled light and autumnal palette of nearby Kew Gardens. Connecting the wings is a glass encased circulation link, allowing light to fill the house and courtyard, revealing the contrast between a rustic exterior and refined interior, where oak veneer panelling and Dinesen flooring are the basis of a warm and natural material palette. An on-site joinery workshop and CNC milling were used to create a bespoke fit-out that could be installed by the client and a small team of architecture graduates. An intricate self-build on a modest budget, Piercy&Company utilised prefabrication technologies to achieve economical but complex forms, allowing the elegant, water-tight outer skin to be installed rapidly. Completed in January 2014, Kew House was an experimental project, driven by the architect’s and clients’ shared interest in a ‘kit-of-parts’ approach, prefabrication, and the self-build possibilities emerging from digital fabrication.