Was your toilet made before 1993? Consider replacing it with a more efficient one.

It's not all about posts and beams. For builders, this is an energy-efficient alternative to traditional wood frame construction. It consists of prefabricated panels of rigid foam insulation surrounded by plywood or oriented-strand board. SIPs provide the structural frame of a building and its insulation in one unit, reducing labor and construction-site waste, and contributing to a very airtight building envelope. SIPs can be used for roofs and gables as well as walls.

Mold isn't just a patch of blue to indicate your bread's gone bad. There are molds that grow on...