It is normal for people in many countries to build their own houses, especially among the poor. Now, a British architect, Walter Segal, has developed a timber-frame building system based on off-the-shelf materials, with a minimum of cutting, and a simple sequence of step by step operations (Appropriate Technology, Vol 2 1, No 4).

The system, says Segal, is highly flexible and allows for buildings to be extended and modified.