Berkeley's Building Emissions Saving Ordinance (BESO) requires residential property owners (1–4 units) to obtain a Home Energy Score (HES) assessment before selling, typically resulting in a 1–10 efficiency rating. The program aims to reduce greenhouse gas emissions by providing transparent energy data, with mandatory compliance before transferring title or through a deferred agreement with the buyer. 


The purpose of the new ordinance is to inform buyers about energy performance, promote sustainability, and encourage energy efficiency improvements. For 1 and 2 unit residential properties in the city of Berkeley, the assessment must be completed before the property is listed for sale (starting January 1, 2026). An approved third-party assessor must inspect the property, which is then scored on a 1–10 scale, where 10 is the most efficient. 


Exemptions: Properties under 850 square feet, certain condominiums, and buildings over 25,000 square feet are generally exempt but make sure you carefully review the official document from The City of Berkeley.


Key Details

  • The City of Berkeley requires a Home Energy Score to be disclosed in MLS listings for applicable properties.
  • Effective date: January 1, 2026.
  • Applicability:
    • Currently applies to single-family homes and duplexes listed for sale in Berkeley.
    • 3–4 unit residential properties will be phased in after 2028.
    • The requirement applies to all on-market listings that fall under the ordinance.
  • Responsibility for compliance rests with the property owner and the listing agent.


Guidance for SFARMLS subscribers

  • MLS data entry:
    • At this time, the Public Remarks field must be used to include the Home Energy Score.
    • There is no dedicated MLS field for the score yet.


If you have any questions about the Berkeley Building Emissions Saving Ordinance (BESO). please reach out the MLS team by opening a ticket here.