HERS Update to Standard ANSI/RESNET/ICC 301-2019
MINHERS Addendum 42 adopted Standard ANSI/RESNET/ICC 301-2019 to replace Standard ANSI/RESNET/ICC 301-2014 as the basis for calculation of the HERS rating. Addendum 42 currently allows voluntary use of RESNET accredited software based on Standard 301-2019 and will require use of Standard 301-2019 on January 1, 2022. See the section 502.3.2 definition for Mandatory Compliance Date.
303.1 Applicable Standards
Exception 1: RESNET Home Energy Ratings conducted in Puerto Rico and the US Virgin Islands shall comply with the provisions of ANSI/RESNET/ICC 301, except that Ratings of homes are permitted to use a default infiltration rate of 10 ACH50 in lieu of conducting an airtightness test in accordance with Standard ANSI/RESNET/ICC 380. In addition, for a home in the Tropical Climate Zone for which its Living Space is not serviced by a space heating mechanical system and not more than one-half of its Living Space is serviced by a space cooling mechanical system, the Conditioned Space Volume shall be defined as the volume of its Living Space and the Conditioned Floor Area shall be defined as the floor area of its Living Space.
Exception 2: RESNET Home Energy Ratings shall be calculated using the modifications of referenced standard ANSI/RESNET/ACCA/ICC 310-2020 established by Addendum 53f and Addendum 89f. (See Addendum 53f) (See Addendum 89f).
Exception 3: RESNET Home Energy Ratings shall be calculated using the modifications of Standards ANSI/RESNET/ICC 301 established by HERS addenda:
- Addendum 53f, HERS Index Calculations Consistency
- Addendum 66, CO2e Index
- Addendum 79, Table 5.1.2(1) Informative Note Correction
- Addendum 78f, Sampling
- Addendum 71f, SEER2 and HSPF2 Conversions
- Addendum 74, Space Constrained Heat Pumps
- Addendum 83, CMU Insulation Grading and R-Values
- Addendum 90i, Service Hot Water
- Addendum 89f, Handheld Watt Meters
- Addendum 85, Temporarily Converted Garages
303.2 Rating Registration
All Confirmed, Threshold and Sampled HERS Ratings shall be registered with the National RESNET Registry in accordance with Sections 102.1.4.10 and 102.1.4.12.
303.3 HERS Rating Tools
All RESNET-accredited HERS Rating Tools shall prohibit printing of Confirmed, Threshold and Sampled HERS Ratings until such rating has been registered with the National RESNET Registry and a unique registration identification has been assigned. Said registration identification shall be prominently displayed on all printed HERS Rating reports.