Architects faced with the need for energy-efficient enclosures have come up with options of using structural insulated panels, that slow down the transfer of heat, air, and vapor. When detailed and built correctly these enclosures are durable and give a high performance.
These insulated panels are made with a core of insulated foam that is sandwiched between two sheathing materials that are made of rigid boards. These boards can be of sheet metal, fiber-cement, plywood or other composite structural-aiding materials. Every sheathing material gives the resulting insulated panel its own characteristics of strength and load-bearing.
Structural panels behave just as columns with wide flanges will do, with the cores acting like the web of a column, and the sheathing acting like its flanges. Thicker cores result in stronger panels that have better resistance to compression and bending. It has been possible to build four-story structures with these panels.