Introduction

Kew House is an experimental project that promotes housing innovation through design-led research exploring a kit-of-parts approach, structural façades, prefabrication and how digital fabrication opens up the possibilities for self-build. Constructed on a tightly constrained site in a conservation area in Kew, South West London, the project was developed by and for the author, Tim Lucas, and his family. Lucas was the client, structural engineer, project manager and contractor.

A significant element of the brief and the resulting architecture was to build the house around a central courtyard. The design was conceived so that the house was presented as two buildings, joined by a glazed circulation link. This strategy breaks up the visual mass of the house, whilst acknowledging the scale and character of the surrounding houses with their layered gabled-roof forms (1-6).

7 View from the courtyard, showing the south side of the building and the glazed link façade.

8

8 Internal courtyard with staircase leading to the basement.

9 Glazed link and steel staircase.

The research focuses on two prefabricated weathering steel (ASTM – Corten B) structures, made in a factory using automated technology and assembled onsite behind retained nineteenth-century brick walls. Weathering steel was chosen for the external envelope based on its surface patina, which would blend in with the colour and texture of the surrounding brick buildings, and the lack of maintenance required on the areas that would face the surrounding properties. The weathering steel superstructure was designed as a self-supporting shell that acts as both cladding and structural building envelope for the roof and internally facing walls (10).

Constructing from within the site boundary became a key factor in the prefabrication, given that the outer edge of the building would be largely set against the perimeter with no available access from neighbouring gardens. Part of the research examined how to construct it offsite and lift it into place from within the confines of the site and adjacent street (3).

10

10 Brick gable wall of original stable building against weathering steel shell of new house.

11 Southerly roof shell against surrounding residential gardens.

12 Early physical model of the design proposal.