Structural insulated panels (SIPs) are high performance building panels used in floors, walls, and roofs for residential and light commercial buildings. The panels are made by sandwiching a core of rigid foam plastic insulation between two structural facings, such as oriented strand board (OSB). Other skin materials can be used for specific purposes. SIPs are manufactured under factory controlled conditions and can be custom designed for each home. The result is a building system that is extremely strong, energy efficient and cost effective. Building with SIPs will save you time, money and labor.
SIP homes go up much faster than traditionally framed buildings. A properly trained SIP installation crew can cut framing time by 55 percent compared to conventional wood framing, according to a third party study conducted by R.S. Means. Panels are manufactured as big as 8- by 24-ft., so entire wall and roof sections can be put up quickly, reducing dry-in time. SIPs are ready to install when they arrive at the jobsite, eliminating the time needed to perform the individual jobsite operations of framing, insulating and sheathing stick-framed walls. Electrical chases are typically provided in the core of panels, so there is no need to drill through studs for wiring.
Structural insulated panels are one of the most environmentally responsible building systems available. A SIP building envelope provides continuous insulation, is extremely airtight, allows for better control over indoor air quality, reduces construction waste, and helps save natural resources. Life cycle analysis has shown that SIP homes have a tremendous positive environmental impact by reducing energy use and greenhouse gas emissions throughout the home’s life cycle. Learn more on our green building page.
The structural characteristics of SIPs are similar to that of a steel I-beam. The OSB skins act as the flange of the I-beam, while the rigid foam core provides the web. This design gives SIPs an advantage when handling in-plane compressive loads. SIPs can be engineered for most applications. Detailed information on the structural performance of SIPs is available from SIPA member manufacturers.
The airtightness of the SIP building envelope prevents air from gaining access to the interior of the home except in controlled amounts. A controlled indoor environment is both healthy and comfortable. Humidity can be controlled more easily in a SIP home, resulting in a home that is more comfortable for occupants and less prone to mold growth and dust mites.
SIPs are compatible with almost any building system. Wall panels can sit on a variety of foundation materials, including poured concrete, blocks, or insulated concrete forms. SIPs are sized to accept dimensional lumber and are seamlessly compatible with stick framing. Builders may choose to build with SIP walls and a conventional truss roof, or stick walls and a SIP roof with little difficulty. SIPs are also popular as a method of providing a well-insulated building enclosure for timber frame structures.
Pricing information can be obtained by contacting any of SIPA’s Manufacturer or Dealer/Distributor members. However, the material price does not reflect the labor savings capable with SIP construction. A study conducted by the R.S. Means shows that building with SIPs can reduce framing labor by as much as 55 percent over conventional wood framing. Builders can also expect decreased jobsite waste disposal costs and savings on HVAC equipment. When all these factors are considered, building with SIPs is often less expensive than other building systems.
SIP construction is recognized by the International Code Council body of building codes, which are used by most jurisdictions in the U.S. For residential buildings, specific construction practices for SIP wall systems are included in Section R614 of the 2009 International Residential Code. For applications beyond the scope of Section R614, the building inspector will typically require a licensed engineer or architect to approve the building plans prior to construction. An engineer’s approval is always required in high wind areas, high seismic zones and commercial buildings.
Air barriers or vapor barriers are not required in SIP buildings because properly sealed SIPs create a code compliant air barrier with a permeability rating of less than 1.0 perm. In addition, the foam core of SIPs is solid and continuous throughout the wall, eliminating the convection and condensation issues that can occur in cavity walls.