Wisconsin Code Alert
Technical Information
Thermal Design Last Update: 08/11/2025
Technical Information / Codes & Standards / Code Finder
Wisconsin
Code Name: Wisconsin Commercial Building Code (2021 IECC)
Based Upon: 2021 IECC
Effective Date: 09/01/2025
Compliance: Mandatory
Thermal Design provides this information as a courtesy and shall not be held responsible or liable for the information explained. Energy code updates, jurisdiction adoptions and enforcement may vary and Thermal Design recommends to check with all current applicable codes as it pertains to your specific project. If you have questions, would like additional information or notice a discrepancy please contact us.
Metal Building Code Alert
The State of Wisconsin has updated the Wisconsin Commercial Building Code (Energy Conservation), SPS Chapter 363, by adopting the 2021 IECC (International Energy Conservation Code™) with compliance as of September 1, 2025. The new energy code increases stringency requiring alternative installation and additional insulation levels for metal buildings roofs and walls. For decades, Thermal Design has been supplying insulation systems that achieve the high level of performance the State of Wisconsin is implementing today.
Minimum Requirements
* Based on 2021 IECC, Table C402.1.3 and Table C402.1.4.
| Climate Zone | Roof | Wall | |
|---|---|---|---|
| 6 | U-factor* | U-0.031 | U-0.050 |
| Installed R-Value | R-32.3 | R-20 | |
| Prescriptive Value | R25+R11Ls | R13+R14ci | |
| 5 | U-factor* | U-0.035 | U-0.050 |
| Installed R-Value | R-28.6 | R-20 | |
| Prescriptive Value | R19+R11Ls | R13+R14ci | |
Exposed Purlins
Roof insulation systems which leave the conductive purlins exposed to the interior DO NOT meet the assembly description for a Liner System (LS) listed within the energy code. (Compare in the chart below)
(LS) Liner System: a continuous membrane installed below the purlins and uninterrupted by framing members. Uncompressed, unfaced insulation rests on top of the membrane between the purlins (2015 IECC, Section C202).
“ci” Continuous Insulation
Fiberglass insulation compressed behind or in front of wall girts and/or fiberglass insulation installed uncompressed between wall girts should NOT be considered “continuous insulation” because it does not meet the assembly description or minimum thermal performance.
(ci) Continuous Insulation: insulation that is uncompressed and continuous across all structural members without thermal bridges other than fasteners and service openings. It is installed on the interior or exterior or is integral to any opaque surface of the building envelope. (ASHRAE Standard 90.1-2013 definition)
Simple Saver® System is the Solution
The installed performance of the Simple Saver® System surpasses the minimum thermal envelope and air barrier requirements (ASTM E2178) in the 2015 IECC and for the State of Wisconsin. Thermal Design has conducted hot box testing in accordance to ASTM C1363 on a variety of Simple Saver roof and wall assemblies that validates installed performance to demonstrate energy code compliance and envelope assembly modeling.
Additional high R-value Simple Saver assemblies are available upon request, including additional options for thru-fastened roof and standing seam roofs without thermal spacer block.
Simple Saver System Performance
| ROOF: SIMPLE SAVER SYSTEM | |||||
|---|---|---|---|---|---|
| Roof Type | Thru-Fastened | Standing Seam | Standing Seam | Standing Seam | Standing Seam |
| Thermal Block | None | None | R-3 | R-3 | R-3 |
| R-VALUE | R-19+R-11 | R-19+R-11 | R-19+R-11 | R-25+R-11 | R-30+R-11 |
| U-Factor | U-0.044 | U-0.040 | U-0.035 | U-0.031 | U-0.029 |
|
Installed R-value |
R-22.7 | R-25.0 | R-28.6 | R-32.3 | R-34.5 |
|
Roof performance based on ASHRAE 90.1-2019, Appendix A for purlins spaced a minimum of 52" oc. R-values listed from inside to outside. Additional assemblies available upon request. |
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| WALL: SIMPLE SAVER SYSTEM (SINGLE LAYER & DOUBLE LAYER) | |||||
|
Note: No ci Continuous Insulation or Rigid Board |
|||||
| R-value | R-25* | R-30* | R-32.4* | R-25 + R-10 | R-30 + R-16 |
| U-factor | U-0.059 | U-0.052 | U-0.049 | U-0.047 | U-0.039 |
|
Installed R-value |
R-16.9 | R-19.2 | R-20.4 | R-21.3 | R-25.6 |
|
Wall performance based on ASHRAE 90.1-2019, Appendix A for girts spaced a minimum of 52" oc. R-values listed from inside to outside. Additional assemblies available upon request. * Quik-Stop foam thermal break tape (3/16") applied to girt flange. |
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Single Layer Wall System shown above.
To learn more about the changes with metal building U-factors and more detailed information on which metal building insulation assemblies that meet code intent call 800.255.0776 or email us.
