A clever designer appreciates the advantages of adaptation, and a smart builder knows that not everything has to be built from scratch. In his Unitec projects, Strachan, an architect who is also an experienced builder, also has to find ways to keep costs down. The roof of the Coromandel bach is formed by structural insulated panel (SIPs) sandwiches of metal coated, 150mm polystyrene with efficient insulation properties. SIPs were designed for use in coolstores. It’s rather fitting that they should be pressed into service on a bach – another familiar Kiwi building type.