New ADU Laws In 2024 – Everything You Need To Know: Update

Nov 2, 2022 | ADU

California legislation has passed new bills that are game changers for ADU development. These clean-up bills signed into law by Governor Gavin Newsom will undoubtedly pave the way to a bigger boom in the construction of additional dwelling units.

From changes in setback regulations to increasing size limitations, it will soon be easier than ever to build the ADU of your dreams. Read on to learn more about the changes that have unfolded in 2023 and what new developments are anticipated in 2024.

Why Are ADU Laws Being Updated?

California has been facing a homelessness crisis for some time now. To combat this crisis, the state government has tried to encourage ADU development by making it more affordable and easier to undergo. ADUs are small, compact units that can provide affordable housing to low-income families, thus helping California housing production keep pace with demand.

New ADU laws passed in 2017 and 2019  left room for improvement. Although Governor Newsom signed into law the CalHFA GrantFreddie Mac made changes to their ADU rules, and many local jurisdictions within the state launched ADU programs, there are still barriers holding people back from constructing units.

Improving upon these laws helps remove unforeseen barriers created when the original laws were written. As a result, more units will be constructed to combat the growing housing crisis plaguing the state of California.

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New AB 221 ADU Law

New AB 221 ADU Law

AB 221 was signed by Governor Newsom on 9/28/22 and has gone into effect as of 01/01/2023. The purpose of this bill is to clarify old legislation to ensure that regulations are easier to understand and cannot be “misinterpreted” to make ADU development more difficult. This new bill entails several important changes to the law.

Redefining Height Restrictions

AB 221 now requires that all cities change their ADU size limits to at least 16 feet. Cities are allowed to have higher height limitations, but they cannot restrict you from constructing your ADU any lower, thus paving the way for more 2-story ADUs. There are added regulations to this new law that require cities to allow you to build even higher than 16 feet.

CircumstanceADU Height Limitation
ADU is attached to the primary dwelling25 ft*
Structure is within ½ a mile from public transit18 ft
Property already has a multi-family dwelling that is two stories high18 ft
All other ADUs that don’t meet above requirements16 ft

* This will also depend on the underlying zoning code of that property. If it is lower than 25ft, then it will be the ADU height limitation.

Of course, this still leaves some questions. For example, you may be wondering if changing height restrictions impacts the maximum size an ADU can be. From our understanding, it will not affect the maximum size of an ADU unless it is a percentage-based ordinance (i.e. an open space requirement). Whether or not this holds true will be better defined when the law goes into effect.

Changes In The 60 Day Rule

In 2020, legislation required that your ADU permit must be approved or denied within 60 days. This encouraged rapid ADU development, but it had a major drawback. Since most cities were being slammed with ADU permits, a lot of planning departments started simply denying permit applications once the 60 days were up.

To try to prevent this from happening, AB 221 now requires that cities write all the reasons an application is rejected, not just a few. That way, they must spend time looking at the application more carefully and not just rejecting it for a minor mistake if time is running out.

The language of the law was also changed from “local agencies” to “permitting agencies.” Therefore, 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 your planning board. How well this can be enforced is another story. We will have to wait and see how well this goes into effect.

Front Setback Better Defined

If an ADU is under 800 sq ft, front setback requirements now cannot prevent an ADU from being built. ADU zoning laws such as floor area ratio and open space ratio are two regulations that previously could not be enforced if they prevent an 800 sq ft or less unit from being built. With the new changes in laws, front setback requirements have been added to the list.

Easier To Build Multi-Family Housing

Currently, you can add an ADU to a pre-existing multi-family building. However, you cannot add one to a proposed multi-family building. As a result, developers have to complete their multi-family building project and then start ADU development once their original project is complete. This is time-consuming and unnecessary.

AB 221 makes it so that builders can propose and build new ADUs in new multi-family housing concurrently. Thus, saving everyone time, money, and headaches.

New SB-897 ADU Laws

New SB 897 ADU Laws

SB-897 was signed into law on the same day as AB 221 and has gone into effect as of January 1, 2023. It is another “clean-up” bill that features a lot of overlapping changes, like increasing height restrictions to allow for more 2-story ADUs. However, there are a few unique provisions to this bill as well.

Dealing With Unpermitted Work

Many cities currently prohibit homeowners from developing ADUs if there is unpermitted work on their property. This can include non-conforming zoning conditions, building code violations, or unpermitted structures. Fixing these issues can take lots of time and money, resulting in ADU development being severely delayed.

SB-897 now eliminates these restrictions unless the unpermitted work is deemed a safety or health concern. If it is not, you do not need to fix it before building the ADU.

No More Fire Sprinklers

The construction of an ADU currently triggers a Group R occupancy change to your property. As a result, you needed to install fire sprinklers in the primary dwelling.

This new bill will eliminate the occupancy change, resulting in no more mandatory fire sprinklers in the primary dwelling.

Clarified JADU Laws

When building an attached JADU, you do not need to include a bathroom in the unit. This new bill makes it more explicit that if you don’t include a bathroom, the bathroom in the primary dwelling needs to be accessible to the JADU. Apparently, this wasn’t explicit enough for some people before.

Improved Demolition Laws

Despite how helpful ADUs are at improving the California housing crisis, some cities are still doing their best to block ADU development. Therefore, to stop garage conversions from being built, many cities issue ADU permits but then withhold the demolition permit needed to tear down the existing garage. As a result, ADU development is halted.

Starting in 2023, cities could no longer withhold demolition permits once the ADU permit was issued. Posting a public notice about the demolition also became unnecessary. As a result, it became harder for cities to block ADU development.

California Accessory Dwelling Unit Fund

SB-897 also adds Government Code 50678 to require that the department establishes a grant program to fund the construction and maintenance of both ADUs and JADUs. Once the legislation determines the amount of funds that will be put towards this program, the department will distribute funds to eligible recipients. We will know more about this fund in the future when all the rules and regulations are hashed out.

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Other ADU Law Updates

Other ADU Law Updates

Although AB 221 and SB-897 are two very big bills that make a lot of changes, other changes were made in 2023 and are expected to come in 2024 as well. Here is a quick overview of a few worth mentioning.

AB 1033 ADU Law

Also known as Affordable Homeownership Units, AB 1033 suggests that individual cities and counties should have the final say on whether ADUs can be sold separately from the main home.

Currently, California law prohibits the sale or transfer of an ADU as a separate property from the primary residence. This amendment aims to change that and provide lower-income households in California with an opportunity for homeownership, especially considering the high average housing costs ranging from $700,000 to $1 million.

By allowing ADUs to have their own addresses and be considered separate properties, this proposal opens up the possibility of ADUs functioning as standalone units, similar to condominiums. This could pave the way for more affordable starter homes to be created in both new and existing buildings.

It’s worth noting that the concept of selling ADUs separately from the primary residence is not new in the United States. Several cities across the country, such as Seattle, WA, Austin, TX, Portland, OR, and Princeton, NJ, have already implemented this approach for years in an effort to address affordable housing crises.

AB 976 ADU Law

AB 976 seeks to permanently eliminate owner occupancy restrictions that currently exist in cities and counties. These restrictions, which prohibit the requirement of the property owner’s occupancy in either the accessory dwelling unit (ADU) or the primary residence, are set to expire soon. However, this new law aims to remove these restrictions permanently.

Studies have shown that areas where owner occupancy restrictions are enforced experience slower rates of ADU construction. Previously, the ADU occupancy requirement mandated that either the primary residence or the ADU had to be occupied for a minimum of five years following the ADU’s completion.

These occupancy requirements also extended to property sales. If the property was sold within the five-year period, the new owner would have to comply with the occupancy requirement for the remaining duration.

The owner occupancy requirement posed a significant obstacle to ADU financing, as it reduced the potential rental income that could be leveraged. This led lenders to perceive homeowners as being at a higher risk of loan default, discouraging them from providing financing for ADU construction or the purchase/refinancing of properties with additional units subject to these restrictions.

Furthermore, these owner occupancy requirements deterred homeowners from pursuing ADU creation. The high costs associated with constructing a secondary dwelling unit, coupled with limited potential for passive income, rendered secondary units financially unviable for many homeowners.

Additionally, the owner occupancy restrictions prevented real estate investors from building ADUs on investment properties or acquiring properties with existing dwelling units to maximize their rental income potential.

AB 916 ADU Law

AB 916 is not directly about ADUs but still applies to them. It makes it so that a city cannot require a public hearing to add a bedroom or two to an existing dwelling unit. As a result, there is the possibility that local jurisdictions may allow you to use this bill to convert garages, attics, basements, and other unconditional spaces into bedrooms. We cannot know for sure, but there is a good chance this will be beneficial to ADU development.

AB 157 ADU Law

The $40k CalHFA Grant has been an incredible asset in encouraging ADU development. AB 157 will make it even better by requiring CalHFA to convene a working group to develop recommendations to make it easier for homeowners to qualify for ADU construction loans. It will also increase access to the capital available for homeowners who are looking to develop ADUs and JADUs.

AB 561 ADU Law

AB 561 is another government-backed ADU finance program known as the Help Homeowners Add New Housing Program. This program was created because many homeowners, even with strong credit scores and favorable loan-to-value ratios, cannot easily access federal government-backed mortgages to finance their ADU. This is because mortgages currently require tenants in place and a year or more of documented rental income.

This program addresses the gap to enable homeowners to take advantage of low mortgage interest rates that are predicted to come in the next several years. It “encourages banks, credit unions, and other mortgage originators to make construction loans to homeowners to bridge existing federally backed loans.”

The purpose of the program is “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.” A lot of the rules still need to be hashed out, but this is looking like it will be a great financing opportunity for individuals looking to build ADUs.

Developing An ADU In California

Thanks to the new California ADU law updates, it will soon be even easier to build an ADU in the state. There will most likely be discrepancies in how jurisdictions interpret and therefore enforce the law. However, it is safe to say these changes will more than likely do more good than harm.

If you are looking to build an ADU in California, reach out to us today! Here at Levi Design Build, we can help you with every step of your ADU development. Contact us today to learn more about our personalized approach and get a free consultation. We look forward to working with you on making your dream ADU a reality.


  • What is the purpose of California’s new AB 221 ADU law?
    The AB 221 law, effective from January 1, 2023, aims to clarify previous legislation to make ADU development regulations easier to understand and apply, thereby facilitating the construction of more ADUs in California.
  • How have height restrictions for ADUs changed under AB 221?
    Under AB 221, cities must now set their ADU height limits to at least 16 feet, allowing for the construction of more 2-story ADUs. Cities can opt for higher height limitations but cannot impose lower ones.
  • What changes does SB-897 introduce regarding ADUs?
    SB-897, effective January 1, 2023, overlaps with AB 221 on some changes like increasing height restrictions. Unique provisions include eliminating restrictions related to unpermitted work (unless it’s a safety concern) and removing the mandatory fire sprinkler requirement in the primary dwelling due to ADU construction.
  • Can ADUs now be added to proposed multi-family buildings?
    Yes, AB 221 allows builders to propose and build new ADUs in new multi-family housing concurrently, which is a change from the previous requirement of completing the multi-family building before starting ADU development.
  • What is the impact of AB 1033 on ADU sales in California?
    AB 1033 suggests that local governments should decide if ADUs can be sold separately from the main home, potentially allowing ADUs to function as standalone units similar to condominiums, thereby promoting affordable homeownership.
  • How does AB 976 affect owner occupancy restrictions for ADUs?
    AB 976 seeks to permanently eliminate owner occupancy restrictions, which previously required the property owner to live in either the ADU or the primary residence for a minimum of five years.