New ADU Laws for 2023 – A Comprehensive Guide

As California continues to grapple with its housing crisis, new legislation has been enacted to simplify and streamline the development of Accessory Dwelling Units (ADUs) across the state. ADU laws AB 221, AB 916, AB 561, and SB 897 were signed by Governor Newsom and came into effect on January 1, 2023. 

These laws make it easier for Californians to build ADUs on their properties by eliminating certain restrictions, clarifying existing legislation, and creating new financing programs. In this article, we will take a closer look at each of these four new ADU laws and how they impact the development of ADUs in California.

Here at GreatBuildz, a free service that connects property owners with reliable general contractors, we get inquiries all the time about ADU laws and guidelines– read below to learn more about the current ADU guidelines in Los Angeles, Orange County, Ventura, or San Diego.

New ADU Laws in Effect in California for 2023

Below is a list of the latest changes to ADU regulations throughout California, as well as what they mean for homeowners and investors considering an ADU for their property.

AB 221 


The new California ADU law, AB 221, was signed by Governor Newsom on September 28, 2022, and went into effect on January 1, 2023. The law clarifies old legislation to ensure that ADU guidelines and regulations are clearer and less prone to misinterpretation, thereby reducing obstacles to ADU development. 

The changes brought about by AB 221 include:

  • Redefining height restrictions – AB 221 requires all cities to change their ADU size limits to at least 16 feet, paving the way for more two-story ADUs. There are also added regulations that require cities to allow ADUs to be built even higher than 16 feet in certain circumstances. For example, if an ADU is attached to the primary dwelling, the height limitation is 25 feet. If the structure is within ½ a mile from public transit or the property already has a multi-family dwelling that is two stories high, the height limitation is 18 feet.
  • Modifications to the 60-day rule – Previously, an ADU permit had to be approved or denied within 60 days. However, many planning departments started simply denying permit applications once the 60 days were up. To prevent this from happening, AB 221 requires cities to specify all the reasons an application is rejected, not just a few. The language of the law was also changed from “local agencies” to “permitting agencies.” This means that any entity involved in the review of an ADU permit (i.e. water districts, utilities, etc.) is held to the 60-day requirement, not just the planning board.
  • Front setback – The front setback requirement for ADUs is better defined in AB 221. If an ADU is under 800 sq ft, front setback requirements now cannot prevent an ADU from being built. 
  • Multi-family housing – AB 221 makes it easier to build multi-family housing by allowing builders to propose and build new ADUs in new multi-family housing concurrently. Previously, developers had to complete a multi-family building project before starting ADU development.

Overall, AB 221 simplifies the ADU development process, eliminates some of the restrictions that may have made it difficult for people to build ADUs, and makes it easier for Californians to have additional housing options on their properties.

AB 916 


AB 916 is a new California law that, while not about ADU laws, has an impact on ADUs indirectly. The law prevents cities from requiring a public hearing to add a bedroom or two to an existing dwelling unit. This means that local jurisdictions may allow the conversion of garages, attics, basements, and other spaces into bedrooms without a public hearing. 

Currently, this does not have a direct impact on ADUs, but it is still an exciting development to watch.

AB 561

adu laws los angeles

AB 561 established a new ADU finance program called the Help Homeowners Add New Housing Program, which was created to help homeowners finance their ADUs, especially those who have trouble accessing federal government-backed mortgages due to various requirements. This program is designed to bridge the gap and enable homeowners to take advantage of low mortgage interest rates that are expected in the coming years.

The program aims to encourage banks, credit unions, and other mortgage originators to provide construction loans to homeowners and bridge existing federally-backed loans. It also seeks to protect participating financial institutions that elect to enroll qualified loans in the program from losses through default by establishing loss reserve accounts for each participating institution. While the details of the program are still being worked out, it is anticipated that this will be a great financing opportunity for homeowners looking to build ADUs.

SB 897

adu laws 2023 los angeles

SB 897 is a “clean-up bill” with many changes overlapping with the other ADU laws above. 

The changes brought about by SB 897 include:

  • Allowing homeowners to develop ADUs even if there is unpermitted work on their property unless the unpermitted work is deemed a safety or health hazard.
  • Eliminating the need to install mandatory fire sprinklers in the primary dwelling upon the construction of an ADU. 
  • Making it more explicit that, if you do not include a bathroom in an attached JADU, you must have a bathroom in the primary dwelling that is accessible to the JADU. 
  • Preventing cities from withholding demolition permits if an ADU permit is issued.
  • Requiring the government to establish a grant program to fund the construction and maintenance of ADUs and JADUs. 

Overall, SB 987 makes it easier to build ADUs by eliminating certain restrictions and ADU requirements and making it harder for cities to block ADU development.  

Build Your ADU

adu garage

Generally speaking, these ADU law updates are great news for anybody interested in building an ADU. If you’re ready to take the next step toward building an ADU of your own, GreatBuildz is here to help.

If you have more questions about the ADU process or how to pick the right contractor for the project, we are always available to assist.

GreatBuildz is a free service that connects homeowners in Los Angeles, Orange County, Ventura or San Diego with reliable, thoroughly screened general contractors and provides project support from start to finish. You can call our friendly staff to be connected to several fully vetted, trustworthy contractors who are experienced with ADUs. For more info, visit or call 818.317.3567 today.

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