The City of Berkeley has frequently pioneered environmental policies that have spread across the country. Its latest example is a Building Emissions Saving Ordinance (BESO) that went into effect this past January. Single-family homes account for 58 percent of U.S. building emissions. In 2006, Berkeley set a target of 80 percent reduction in greenhouse-gas emissions by 2050. Since buildings are the second-largest source of carbon emissions after transportation, there have been many efforts in California and elsewhere to make buildings cleaner and more energy-efficient.
In 2019, Berkeley became the first community in the country to ban natural gas hookups in new construction. Many other jurisdictions, including Santa Barbara, promptly took similar action. This approach was thwarted, however, when the California Restaurant Association successfully sued to halt the ban.
Following this disappointing setback, efforts intensified to find ways to improve the energy performance of older homes. The Berkeley BESO ordinance now requires sellers and buyers of homes to replace fossil-fuel appliances or make other green upgrades as a condition of sale. Some municipalities require home sellers to obtain and disclose the results of energy audits to encourage adding voluntary efficiency features. Improvements, however, have been paltry to date.