New Changes to Title 24 Coming in 2023

Learn about the upcoming changes to California’s Title 24 energy code and the impact they'll have on ADU and JADU development.

Last updated 
December 22, 2022
New Changes to Title 24 Coming in 2023

New Changes to Title 24 Coming in 2023

Along with new ADU laws, there are also new updates to California’s Title 24 energy code set to go into effect in 2023. While most of the new changes don’t apply to accessory dwelling units, some of them will.

In the following post, we’ll explain what Title 24 is (and why it exists), outline the new changes, and clarify the impact they’re likely to have on ADU development.

What is Title 24?

Title 24 is the state of California’s Building Energy Efficiency Standards. According to the California Energy Commission, the energy code is designed “to reduce wasteful and unnecessary energy consumption in newly constructed and existing buildings." The goal is twofold: to decrease the state’s greenhouse gas emissions while making the energy system more resilient in the face of increased climate crisis.

In an effort to ensure maximum efficiency and impact, the energy code is updated every three years. The last set of updates were passed in 2019 and went into effect in 2020, while the 2022 updates will begin on January 1st, 2023.

What are the new Title 24 changes?

The 2022 Title 24 update includes a number of changes that impact a wide range of residential and commercial buildings. The updates are too numerous and specific to fully include here, but they impact the following aspects of development:

  • Construction materials
  • HVAC systems
  • Water heaters
  • Indoor and outdoor lighting
  • Solar energy and energy storage

How will the changes impact new ADUs?

As we mentioned above, not all of the new changes impact accessory dwelling units. However, a few of the Title 24 updates do have implications for ADUs and JADUs.

Unlike larger residences, ADUs under 500 square feet can opt for a space-efficient electric tankless water heater system, thereby avoiding natural gas and allowing for a fully electric unit. In addition to the space savings (which are always appreciated when working with a tight floor plan), this option can also save money: installing a gas line can be costly, and a fully electric unit avoids this expense.

ADUs larger than 500 square feet must follow single family home guidelines and install a heat pump water heater.

ADUs under 500 square feet are now exempt from ventilation cooling requirements that apply to larger residential units (including larger ADUs).

There are additional requirements that may impact accessory dwelling units depending on your climate zone. If you have any new questions about the updated Title 24 guidelines and whether they apply to ADUs, call or email California’s Energy Standards Hotline.


It can be confusing to keep up with new energy code changes and whether or not they apply to accessory dwelling units. It’s also possible that the updated HVAC requirements could lead to price increases as manufacturers work to adjust their production line. Despite these potential downsides, Title 24 helps keep our planet and its residents safe and healthy. We applaud the state of California for its commitment to greenhouse gas reduction and energy efficiency for a greener future.

If you’re planning on building an ADU in 2023, work with an expert like Otto to make sure your accessory unit is Title 24 compliant. Our designers and contractors are up-to-date on the latest energy code requirements and always source code-compliant materials and appliances. Contact Otto for a free property evaluation to start planning your beautiful, energy-efficient ADU.

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