Think of an Oreo cookie, and you've got the idea about a structural insulated panel (SIP). SIPs are made from a layer of foam insulation that's sandwiched between pieces of plywood, strand board or cement panels.
In 2009, the material was used in less than 2 percent of new homes.
By some estimates, SIPs save 50 percent in energy costs over houses built from conventional materials [source: NAHB Research Center]. But some people think they're ugly, and architects generally don't have much experience using the material.
According to the National Association of Home Builders, the material is fire resistant, and it can be used for foundations, floors, basements and load-bearing walls. And as to the aesthetic issues, the association's research notes that the surfaces can be given finished looks, such as wood grain or stucco. Siding, bricks and stone can be installed on the panels, too.