County of Marin

Frontrunner: County of Marin


One of the smallest counties in the state, Marin County maintains an outsized impact in many respects. The county is home to some of the most iconic landscapes in the world, boasts public buildings designed by Frank Lloyd Wright as well as Skywalker Ranch, a creative filmmaking hub, and perennially makes the top list of America’s wealthiest counties.

The County takes pride in its leadership role for energy efficiency and sustainable building practices, with local provisions in effect for nearly twenty years. In mid-2018, the County undertook a substantial upgrade of its Green Building Ordinance to update legacy requirements and incorporate new standards for buildings in Marin to be more energy efficient, comfortable, and affordable to operate. In 2019, the County targeted additional reach provisions linked to the statewide 2019 Energy Efficiency Standards that would extend those 2018 policies to better align with the County’s environmental goals and ensure that requirements are easy to understand and implement.

Scenic Sausalito
Scenic Sausalito is one of Marin County’s most iconic locations.
Green Building Project
Green building project in Marin County.

Collaboration is Key to County Success

Marin County is made up of twelve jurisdictions (including the unincorporated area), all with populations below 100,000 and most with fewer than 15,000. “Because each jurisdiction is small, collaboration allows Marin’s local governments to have a larger impact than we would have acting individually,” says Alice Zanmiller, Marin County Planner, “and alignment of policies and messaging around reach codes really supports implementation.” County staff participate in the Marin Climate Energy Partnership monthly as well as other regional organizations including The Bay Area Regional Energy Network (BayREN), a collaboration of the nine counties that make up the San Francisco Bay Area.

In developing the reach code update, the County led a process that included building department and sustainability staff from multiple Marin County jurisdictions, each weighing in on potential opportunities to exceed the state’s standards. Mill Valley also adopted the standards in 2019, and more jurisdictions are considering the standards in 2020. County staff are supporting adoption in other jurisdictions in an effort to increase consistency. As Zanmiller notes, “we believe this close collaboration meets the requests from our stakeholders and has been successful, as several jurisdictions regionally are following similar frameworks in their efforts to adopt and implement reach codes.”

In evaluating what specific provisions to include, Zanmiller reflected, “We recognized that flexibility is vitally important; for instance, gas cooktops and gas fireplaces are highly desirable by some of our residents and builders. These end uses are relatively small gas consumers compared with gas space or water heating appliances so we created flexible options to enable applicants to comply while still achieving the County’s GHG reduction goals.”

The package of reach codes adopted by the County in October 2019 and approved by the California Energy Commission in December 2019 includes energy efficiency and electric vehicles as show on the right.

Energy Efficiency

Single-family (SF) & low-rise multi-family (MF):

  • All-electric OR
  • Limited mixed-fuel with Energy Efficiency EDR margin equal to or greater than 3 (SF) or 0.5 (MF), and prewired for induction stove OR
  • Mixed-fuel with Energy Efficiency EDR Margin equal to or greater than 3 (SF) or 0.5 (MF) AND Total EDR Margin equal to or greater than 10, and pre-wired for induction stove

High-rise multi-family:

  • All-electric OR
  • Limited mixed-fuel, 5% compliance margin, pre- wired for induction stove OR
  • Mixed-fuel, 10% compliance margin, pre-wired for induction stove


  • All-electric OR
  • Limited mixed-fuel, 5% compliance margin, pre- wired for induction stove OR
  • Mixed-fuel, 10% compliance margin, pre-wired for induction stove

Electric Vehicles

New Construction

Single-family & two-family:

  • Requires an EV-Ready dedicated branch circuit for Level 2 EV charging (240V)

Multi-family (low- and high-rise):

  • One EV-capable space per dwelling unit


  • Select an option from different combinations of EV-Charging, EV-Ready and EV-Capable spaces.

Additions and Alterations

Requirements for all occupancies depend on project scope.

While the ordinances set progressive standards for new homes, County staff acknowledges that ongoing work, such as that being done by the County’s Sustainability Team to promote and provide financial incentives to property owners for energy efficiency and electrification in retrofits and remodels is also important, given the fact that large new developments are uncommon in Marin. The County collaborates in programs such as BayREN’s Single Family and Commercial programs and operates Electrify Marin to provide opportunities for all buildings to reduce their carbon footprint, save money, and support a healthier built environment.


The County maintains a comprehensive online portal here:

The County’s reach code package and related documents are available from the California Energy Commission Docket:

Marin County Staff Report:

Marin County’s Ordinance:

Green Building Guides:

Nonresidential Cost Effectiveness Study:

Residential Cost Effectiveness Study:

Other Frontrunners

  • SDGE - A Sempra Energy Utility
  • Southern California Edison - An EDISON INTERNATIONAL® Company
  • PG&E Corporation

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