2018 IECCOverview

Using FPIS-ci provides one of the most effective means of complying with the energy code because it insulates the entire structure to minimize thermal bridging of framing materials (see STEP 5 for more uses to mitigate other types of thermal bridges). FPIS-ci also provides one of the more robust means of satisfying the moisture control requirements of the building code (refer to STEP 3). Depending on your climate, FPIS-ci may be required if the prescriptive compliance path is being used (e.g., the simple R-value compliance method). Consequently, this design guide assumes the use of FPIS-ci on exterior walls. 

This section addresses determining the R-value of FPIS-ci for energy code compliance. The FPIS material R-value specified and the FPIS material type selected (e.g., XPS, EPS, or PIC) will affect the thickness of the continuous insulation layer on the exterior of the wall. This thickness may affect other construction details, such as cladding connections (see STEP 5 later).

Choose the applicable building type:

  • For one- and two-family dwellings, go to STEP 1A.
  • For commercial and multi-family buildings, go to STEP 1B.

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