For modern architects experimentation with space and the house plan provides the most fertile area of innovation, allowing them to push established boundaries and question received conventions in domestic design. As we enter the 21st century, the incorporation of greater flexibility into housing has become a matter of urgency. The traditional notion of the family unit is being exploded. Small domestic groupings have become dispersed, with the fragmentation of familites and more people choosing to live alone. At the same time, the pressure put on space by multiple marriages and extended families means that the requirements for our home are never still, as they constantly expand and contract. The conventional layout for suburban housing can no longer sustain or cater for changing social needs. This Architectural Design title fully explores the concept of transformability in house design. Through a set of introductory essays by Iain Borden, Catherine Croft, James Gallie, Dennis Sharp, Stefan Muthesius and Miles Glendinning, the roots of this phenomenon are examined in 20th-century design. It is, however, through the eleven case studies of contemporary architects' projects that the concept of transformability is stretched to its full. It is revealed to mean many things - the integration of technology into the home, the use of modular systems to facilitate construction and planning and the development of complex devices for modifying and customising architectural space on a day-to-day basis.