Permit Pathways
There are multiple ways to demonstrate compliance with 2015 IECC at the permit stage. REScheck software can only demonstrate compliance via the Prescriptive/UA Tradeoff permit pathway. In contrast, Home Energy Rating System (HERS) software (i.e., REM/Rate, Ekotrope) can be used to demonstrate compliance via the Performance and HERS Index permit pathways as well as the Prescriptive/UA Tradeoff permit pathway.
Insulation & Windows (Prescriptive)
The table below only includes Prescriptive changes from 2009 IECC to 2015 IECC. All of the 2015 IECC insulation requirements, including those that did not change from the 2009 IECC, are detailed in 2015 IECC Table R402.1.2.
*Pennsylvania amended 2015 IECC for all Climate Zones to allow R-18 in place of R-20 provided wall framing factor is 20% for exterior walls with 24” o.c. nominal vertical stud spacing.
Air Handler/Furnace (Mandatory)
The majority of air handlers and furnaces meet the new requirement. More information can be found on the equipment cut sheet. (2015 IECC R403.3.2.1)
Lighting (Mandatory)
Requirements detailed in 2015 IECC R404.1. High Efficacy is defined in 2015 IECC R202
Duct Leakage (Prescriptive/Mandatory)
Duct Leakage does not have to be tested if all of the ducts are within the thermal envelope, however the ducts must be sealed as per the IRC. (2015 IECC R403.3.4)
Envelope Leakage (Mandatory)
Pennsylvania amended 2015 IECC to increase allowable building infiltration rate from 3 ACH to 5 ACH. (2015 IECC R402.4.1.2)
Plumbing Insulation (Prescriptive)
This requirement is Prescriptive and only applies to Prescriptive/UA Tradeoff permit pathway. Performance and ERI permit pathways are exempt from plumbing insulation requirements. (2015 IECC R403.5.3)
Other Requirements
- Construction documents submitted for permitting must include the following: insulation materials and their R-values, fenestration U-factors and solar heat gain coefficients (SHGC), mechanical system design criteria, mechanical and service water-heating system equipment types, sizes and efficiencies, duct layout, insulation and sealing details, and air sealing details. (2015 IECC R103.2)
- Wall assemblies for the thermal envelope shall have a vapor retarder. (2015 IECC R402.1.1 - Prescriptive)
- Wood burning fireplaces must have tight-fitting flue dampers or doors, and outdoor combustion air intakes. (2015 IECC R402.4.2 - Mandatory)
- Where using tight-fitting doors on factory built fireplaces, doors must be listed and labeled in accordance with UL.127. (2015 IECC R402.4.2 - Mandatory)
- Hot water boilers that supply heat to the building through one- or two-pipe heating systems shall have an outdoor setback control that lowers the boiler water temperature based on the outdoor temperature. (2015 IECC R403.2)
- Kitchen exhaust systems capable of exhausting more than 400 CFM shall provide makeup air into the same room in which the exhaust system is located or into rooms or duct systems that communicate through one or more permanent openings with the room. (2015 IRC – M1503.4)
Mechanical Ventilation (Mandatory)
If ventilation is provided using air handler (i.e., “Air Cycler”), the air handler motor must be an Electronically Commutated Motor (ECM). (2015 IECC R403.6)
Continuous Whole-House Mechanical Ventilation Airflow Rate Requirements - 2015 IRC Table M1507.3.3(1)
Intermittent Whole-House Mechanical Ventilation Rate Factors a,b - 2015 IRC Table M1507.3.3(2)
Fan Efficacy Requirements
