HERS Amendment Adjusts Ratings for Smaller Homes

On January 1st, 2019, a new HERS amendment will take effect. RESNET recently announced the adoption of a home size adjustment factor to address the discrepancy calculation between larger and smaller homes that have similar energy efficiency features. Previously, larger homes received lower HERS Index Scores than smaller homes.

The new standard amendment revises HERS Index Score calculations to address this issue. The amendment establishes a calculation methodology that compensates for size in order that similarly configured and equipped dwellings of different sizes will have equivalent ratings.

HERS Raters will be required to use the size adjustment compliant software on homes that are issued a building permit on or after January 1, 2019. Homes that were issued a building permit before January 1, 2019 may be rated without complying with the new size adjustment factor. Builders can, however, use the new version of software now voluntarily.

RESNET’s new amendment will allow a level playing field between homes constructed with similar environmentally-driven factors, decreasing the difference in HERS scores from 10.8 points to 2 points, according to EnergyGauge USA.

The National Association of Home Builders (NAHB) notes that “the timing of the amendment coincides with the overall decrease in new home size.” With sizes of the homes getting smaller to meet the demand of millennial and new-comer buyers, the demand for green homes continues to stay steady. NAHB research has shown that energy-efficient strategies, including ENERGY STAR-certified appliances and windows and above-code insulation, are on “the most wanted” list of home features.

The new HERS amendment will put smaller homes on the map, while allowing builders to appropriately market energy-efficient homes to the masses.