I studied Architecture at Cambridge from 1960 to 1965, and after graduating joined the newly formed Centre for Land Use and Built Form Studies at Cambridge (later the Martin Centre). I worked on university planning, and on people’s use of time in towns. In 1972 I was a visiting research fellow at Princeton University. In 1977 I went to the Open University to join the Centre for Configurational Studies, a research group brought together by Lionel March. I was the Director of this group until 1998. I worked first at the OU on mathematical methods for representing and enumerating small rectangular plans. This led on to studies of the British housing stock, and studies of non- domestic buildings. I have been particularly interested in the relationship of energy use both to the forms of buildings, and to land use patterns and transport networks in cities. I have carried out, with colleagues, a series of studies of fuel use in buildings and in transport in cities using integrated land-use and transport simulation models. From the early 90s I have worked for the UK government, with large teams, on modelling the building stock of England and Wales and its use of energy. This work began at the Open University and has continued at UCL, which I joined in 1999. My colleagues and I have developed the 3DStock method for modelling building stocks, one application of which is the London Building Stock Model, delivered to the Greater London Authority in 2020.

I have worked since the 1960s on geometry and architecture, on methods for the representation of the forms of buildings, and the enumeration of ranges of possible plans and built forms. This has led on to studies of the histories of building types. I have published several books in these subjects including The Geometry of Environment (with Lionel March, 1971), and Architectural Morphology (1983). My study of The Evolution of Designs: Biological Analogy in Architecture and the Applied Arts came out in 1979 and was republished in an updated edition in 2008. I have also written books on energy and buildings, American cities, the effects of nuclear attack on Britain, and the painting technique of Johannes Vermeer (Vermeer’s Camera, 2001). Building Types and Built Forms, a book about buildings considered from both historical and geometrical points of view, appeared in 2014. My collection of essays and papers on architectural geometry, Why Are Most Buildings Rectangular? came out in 2017. A new book on Renaissance Fun: The Machines Behind the Scenes was published in April 2021