In 2018, California gave final approval to updated building codes that require all new homes to come with solar attached. Multifamily units below three stories must also adhere to the mandate.
The California Energy Commission passed the measure in May 2018 as an update to the state’s 2019 Title 24, Part 6, Building Energy Efficiency Standards. In December 2018, the California Building Standards Commission (CBSC) signed off on the plan — a first of its kind for the nation.
The new standards require that all new homes under three stories high install solar panels starting January 1, and that solar systems must be sized to net out the annual kilowatt-hour energy usage of the dwelling. The codes also incentivize “demand-responsive technologies,” including battery storage and heat pump water heaters. Combined with a host of other energy-efficiency upgrades, the revised building codes are expected to slash energy use in new homes by more than 50 percent.