This bill authorizes cities and counties to require owners of certain residential units to obtain and make available a home energy performance report before the residence may be publicly advertised for sale. Covered residences include single-family detached dwellings, duplexes, triplexes, quadplexes, cottage housing, townhouses, and attached accessory dwelling units. Any local ordinance imposing this requirement must take effect one year after adoption and may not be required until the locality has completed an analysis of the financial impacts on low-income home sellers and adopted a mitigation program that must include subsidizing the cost of reports for low-income sellers. The bill sets required contents for the home energy performance report (including a home energy score using U.S. Department of Energy methods, fuel-specific annual energy use and cost estimates based on the serving utility’s current average annual retail price, at least one comparison score, identified efficiency measures and the most significant improvements, and greenhouse gas emissions by fuel type with comparison context). Reports must be prepared by a qualified home energy auditor certified by a program approved by the U.S. Department of Energy, must follow a standardized format the Department of Commerce develops, and may be replicated for multiple units with identical design and features. A report is valid for eight years after the assessment date provided no relevant changes to mechanical systems, building envelope, energy efficiency, or square footage occurred. The Department of Commerce must develop and make available the standardized report format by November 30, 2025. Legally, the act adds new sections to chapter 19.27A RCW and chapter 43.21F RCW, creating new local procedural and regulatory requirements for pre-sale home energy reporting rather than a new criminal offense or penalty change. Affected parties explicitly include cities and counties, covered home sellers, low-income home sellers, qualified auditors, the Department of Commerce, and utilities. The extracted text does not include formal statutory definitions for "home energy performance report" or "home energy auditor," details or standards for the required financial-impact analysis or mitigation program beyond subsidization, nor does it specify enforcement mechanisms, penalties, or funding sources.

If a city or county adopts an ordinance under this bill, owners trying to publicly advertise the sale of single-family homes, duplexes, triplexes, quadplexes, cottage housing, townhouses, or attached accessory dwelling units will generally need to obtain a home energy performance report before listing. Reports must follow a Department of Commerce standardized format (to be made available by November 30, 2025), use a U.S. Department of Energy home energy score and DOE‑approved auditor certification, include energy use and cost estimates by fuel, greenhouse gas emissions, comparisons and recommended efficiency measures, and remain valid for eight years if no qualifying changes are made. Local ordinances cannot take effect until one year after adoption and only after the locality completes a financial‑impact analysis for low‑income sellers and adopts a mitigation program that includes subsidizing report costs for those sellers. The people most affected are home sellers, who will face the time and likely expense of obtaining certified energy assessments (though subsidized for low‑income sellers per local mitigation programs); city and county governments, which must analyze impacts, design and run mitigation/subsidy programs, and may add local criteria to the report; and energy auditors, who must hold DOE‑approved certification to prepare reports. The bill leaves open key implementation details — how subsidies are funded, the specific standards for the mitigation programs, enforcement and penalties, and precise definitions of report/auditor terms — so those practical costs and administrative burdens will depend on how localities and the Department of Commerce fill in those gaps.