Council weighs HERS target as state law limits local energy rules for small homes

At a work session on the 2024 building codes, staff recommended setting the energy rating index (HERS) to 60 for the local code, a higher (less strict) number than the 2024 IRC default of 53 but tighter than the current adopted 2018 baseline. Brian said the recommendation aims to balance energy performance goals with local market and contractor concerns.

“We're suggesting that we set it at 60,” Brian said, explaining the compromise reflects what many neighboring Johnson County cities are proposing. He noted the 2024 code's unamended energy index is 53 — a substantially stricter standard — while the city's current position under 2018 is about 80 in some references; staff recommended 60 to be more in line with peer cities.

Staff cautioned that Senate Bill 418 (the Buy Right Housing Development Act) limits review periods for certain single‑family homes and permits builders of detached homes under 2,500 square feet to use the 2018 IRC in some circumstances. Brian summarized the state law: “They passed senate bill 4 18 ... it limits a review period for new construction to 30 days.” Council members discussed the practical effect: staff estimated Mission averages about two new single‑family permits a year that would fall under that provision, limiting the number of locally affected small homes but prompting consideration of incentive approaches (fast‑track permitting, fee waivers) to encourage higher performance on other projects.

Council members requested more detailed cost and payback data comparing HERS targets (53 vs. 60) and the staff agreed to provide further analysis during stakeholder outreach.