SIP Energy Efficiency

The energy efficiency of SIP structures is usually the most important quality of SIPs for our homeowner clients and the architects and designers they employ.

Long-term benefits of using Premier panels provide considerable saving when compared to stick framing, even when designed and framed with energy efficiency in mind. A home designed to maximize efficiency using the Premier SIP System consistently performs 50% to 70% better than the Model Energy Code. Savings from lower energy consumption to heat and cool the home continue for the entire life the home and are especially great in areas with extreme weather. This energy efficiency also is beneficial by increasing the resale value of the home. There are two primary ways SIPs provide this drastically improved efficiency: 1) higher effective thermal resistance, and 2) reduced air leakage.

1) SIPs provide higher R-values than stick framed (and insulated) walls and roofs of equal thickness. The R-value of an assembly is a measurement of its ability to resist heat flow. Higher R-values represent higher resistance to heat transfer, which translates to reduced energy consumption for heating and cooling.

2) SIP structures are not more energy efficient simply because of the higher insulating values of the panels, but panels also reduce air leakage, a major source of energy loss in most buildings. With stick framing, it is much more difficult to create a consistent tight seal throughout the home or building, which results in air leakage. The greater the air leakage, more severe the reduction in energy efficiency.

For example, a 2x6" wall with R-20 batt insulation yields an effective thermal resistance of R-16.8. A six-inch Premier SIP System wall (which actually measures 6 1/2 ") has an effective thermal resistance of R-22.3, which is 33% greater. Considering roofs, a 2x12" joist roof with R-35 batt insulation has an effective value of R-31.9. Compared with the slimmer ten-inch Premier SIP System roof (which actually measures 10 1/8 ") that has an effective thermal resistance value of R-35.8, the thinner SIP roof provides 12% greater insulating value than the joist roof.

It has become a common practice in many areas to test homes and buildings for energy efficiency by measuring air tightness through blower door tests. Properly installed Premier panels provide a very tight "closed cavity" that consistently performs well during and after these tests. In fact, ORNL evaluations of a SIP test room revealed the SIP room to be fourteen time more airtight than an equivalent room with 2x6 construction, sheathing, insulation, and drywall. For this reason, the EPA does not require a blower door test for homes built with SIP walls and a SIP roof.

EPA National Director for Energy Star Homes Sam Rashkin estimated the additional costs of materials necessary for a stick built home to meet the new Energy Star Standards between $600 and $1,200 for materials only (prior to 2006). If obtaining an Energy Star rating, there are also additional savings if the entire home envelope is built with properly installed SIPs (exterior walls and roof) because a blower door test or a duct blaster need will not need to be performed, reducing overall rating costs.

The most energy efficient buildings and homes can be accomplished by integrating both the structural insulated panels used on all exterior walls and roof with insulated concrete forms (ICFs) used in floor and ground-level components. Incorporating other energy efficient products, especially doors and windows, should produce substantial long-term savings through reduced energy consumption.

Ease of installation
Structural performance