Iowa State Energy Code, based on the 2012 IECC (Commercial & Residential)
The Iowa State Energy Code (661 Iowa Administrative Code, Chapter 303) applies to all commercial construction, whether new construction or construction work on existing buildings. These requirements also apply to all new construction of one and two family residences in the state, but not to renovation or remodeling of one and two family residences.
Iowa Code Chapter 103A affords local jurisdictions discretion to adopt other building codes or no building code at all. However, it also establishes that certain portions of the State of Iowa Building Code, including energy conservation requirements, apply to construction statewide (local jurisdictions are allowed to adopt the latest edition of a nationally-recognized energy code in lieu of the requirements in the State Building Code).
2012 IECC Amendments (Residential):
-Air Infiltration: Air tightness requirement changed from 3 ACH50 to 4 ACH50
-Duct Tightness: Changes requirements from only allowing total duct leakage testing at 4 cfm/100 sq ft to allowing two options: total leakage of 6 cfm/100 sq ft or 4 cfm/100 sq ft leakage to outside.
-Building Cavities: Allows interior building cavities to be used as return ducts; if building cavities are used as return ducts, they must be sealed and tested for tightness with the entire duct system (even if all ducts are located within conditioned space).
-Above-grade wall insulation: Climate Zone 6 prescriptive value changed from (R-20 + 5 or R-13 + 10) to (R-20 or R-13 + 5); U-factor table remains unchanged
Exempts additions and renovations from the code
Iowa Code Chapter 103A affords local jurisdictions discretion to adopt other building codes or no building code at all. However, it also establishes that certain portions of the State of Iowa Building Code, including energy conservation requirements, apply to construction statewide (local jurisdictions are allowed to adopt the latest edition of a nationally-recognized energy code in lieu of the requirements in the State Building Code).
2012 IECC Amendments (Residential):
-Air Infiltration: Air tightness requirement changed from 3 ACH50 to 4 ACH50
-Duct Tightness: Changes requirements from only allowing total duct leakage testing at 4 cfm/100 sq ft to allowing two options: total leakage of 6 cfm/100 sq ft or 4 cfm/100 sq ft leakage to outside.
-Building Cavities: Allows interior building cavities to be used as return ducts; if building cavities are used as return ducts, they must be sealed and tested for tightness with the entire duct system (even if all ducts are located within conditioned space).
-Above-grade wall insulation: Climate Zone 6 prescriptive value changed from (R-20 + 5 or R-13 + 10) to (R-20 or R-13 + 5); U-factor table remains unchanged
Exempts additions and renovations from the code
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