Houses built out of foam sandwiches are both eco-friendly and strong enough to withstand earthquakes. Meet the SIP, or Structural Insulated Panel–a thick layer of foam insulation pressed between two sheets of plywood or oriented strand board.
SIP homes are so airtight that the EPA has waived its blower door test requirement for SIP houses. Because the amount of insulation is consistent throughout the panel, SIP walls have better insulating qualities than traditional walls with fiberglass insulation applied onsite. SIP homeowners can save up to 60% in energy costs.
For those who prefer natural materials, SIPS with a straw core made from renewable agricultural waste are available, but the foam insulation outperforms the straw. The foam is 98% air, free of ozone-depleting CFCs, manufactured using heat and steam, recyclable, and “requires only a small amount of petroleum to produce,” according to the Structural Insulated Panel Association (SIPA). SIPA asserts, “The average SIP home saves nineteen times the energy it took to make the EPS insulation in the first year of installation.”
The versatile SIP can be used for walls, roofs, or flooring. Because SIP homes require no structural lumber, they use far less wood than a traditionally framed home. The trees used in the oriented strand board are fast-growing and harvested young, so no old-growth lumber is used.
SIPs are prefabricated and custom measured for each project. SIP manufacturers often recycle their waste foam into other products. The panels install easily and produce little construction waste.
A SIP building costs about the same as a traditional structure. The SIPs themselves are more expensive, but the cost of labor is less. Homeowners are often pleased to see how quickly their SIP homes take shape.
With SIPs, you get energy efficiency, waste reduction, and resource conservation–not bad for a foam sandwich.
