A statewide exemption ADU is an ADU of up to 800 square feet, 16 feet in height, as potentially limited by a local agency, and with 4 feet side and rear yard setbacks. ADU law requires that no lot coverage, floor area ratio, open space, or minimum lot size will preclude the construction of a statewide exemption ADU.
2024 Guide to California's New ADU Law
Accessory Dwelling Units (ADUs) and Junior Accessory Dwelling Units (JADUs), also known as Granny Flats, In-Law Units, or Guest Houses, have gained significant popularity for various reasons:
- Property Value: ADUs enhance your property's value.
- Affordable Construction: They are an economical construction option, particularly for garage conversions.
- Rental Income: They provide a source of rental income, especially with rising rental prices.
- Family Housing: They offer affordable housing for extended family members while maintaining privacy.
- Aging in Place: They allow seniors to age in place with flexible shared living areas.
As of 2024, the State of California continues to enact new ADU laws that lift restrictions and make it easier and more affordable to build ADUs. Due to these new laws, ADU construction in California has surged, with over 80,000 ADUs permitted since the first ADU reform bill was passed in 2016.
Here are some key highlights of the new California ADU laws that took effect in January 2024:
New Law - AB 1033
Historically, California permitted local agencies to prohibit the separate sale of ADUs from the primary dwelling for owners, investors, and developers. However, Assembly Bill 1033 now allows homeowners to sell one or more ADUs separately from their primary residence. This law authorizes local agencies to adopt ordinances enabling ADUs to be sold as condominiums, with approval from the California Department of Real Estate. Homeowners may also consider creating a Homeowners Association (HOA) between the primary residence and the ADU to manage common property.
New Law - AB 976
Currently, California ADU laws prohibit local agencies from imposing "owner-occupancy" conditions on ADUs permitted between Jan. 1, 2020, and Jan. 1, 2025. Assembly Bill 976 extends this prohibition indefinitely, preventing local agencies from imposing owner-occupancy requirements on new or converted ADU projects permitted after Jan. 1, 2025. However, local agencies can still impose owner-occupancy requirements on Junior ADUs.
New Law - AB 434
Assembly Bill 434 requires all California cities and municipalities to have a pre-approved ADU plan scheme in place by January 1, 2025. In order for plans to be pre-approved for use by applicants or other property owners in the future, cities must review and accept submissions for them, typically by an architect. Cities may choose to charge a fee to access the designs, and for processing, as well as for modifications required to meet property-specific requirements.
Re-cap of laws that went into effect January 2023:
Changes to the 60-Day Rule
Assembly Bill 2221 requires all agencies involved with reviewing California ADU plans, including planning departments and utility companies, to respond within 60 days of submission of plans. This change reduces the time for application review and processing.
Revised ADU Height Restrictions
AB 2221 also amended the height restrictions as follows:
16 ft: Allowed under any circumstances.
18 ft: Allowed if the proposed ADU is within ½ mile of public transit or the property already has a multi-family dwelling two stories high.
25 ft: Allowed if the ADU is attached to the primary dwelling, depending on the underlying zoning code of the property (the lowest will apply).
Redefined Setbacks
Previously, setbacks were reduced to four-foot side and rear yards. Now, California law states if a proposed ADU is less than 800 sq. ft., the front setback requirement can no longer prevent the ADU from getting built.
Unpermitted Conditions
Senate Bill 897 eliminates the restriction regarding non-conforming zoning conditions, building code violations, or unpermitted structures. Prior to SB 897, homeowners were required to have unpermitted structures brought up to current codes, which made California ADU development slower and more costly. SB 897 removes these restrictions unless the unpermitted condition is a health or safety concern.
Fire Sprinkler Requirement
SB 897 allows fire sprinklers to no longer be required for the main dwelling when permitting an ADU.
Other Changes Worth Mentioning
Attached JADUs no longer need their own bathroom, provided one is accessible in the primary dwelling.
Demolition permits can no longer be withheld if the ADU permit has been issued.
The creation of the California ADU Fund to provide assistance to eligible recipients.
Re-cap of laws that went into effect January 2022
Senate Bill 9. This relates to duplexes and lot splits. SB 9 provides for the ministerial approval of converting existing homes occupied by a homeowner into a duplex if certain eligibility restrictions are satisfied. It also allows a single-family home lot to be split into two lots, and a duplex to be built on each lot, provided that the initial home is occupied by the owner as their primary residence for at least three years.
Some key points of SB 9:
Projects must be for residential use only.
Properties are within an urbanized area designated by the City and are not within agricultural, historic, and very high fire severity zones.
Parking requirements need to be met unless ½ mile from a public transportation stop.
The project will be subject to local short-term rental requirements.
May include connected structures (duplex) if they comply with building code safety standards.
If a lot is split, the project may be subject to City or County easements and must be roughly split in half.
Lots must meet minimum size requirements for a lot split.
The lot cannot be adjacent to another lot that has been split using SB 9.
Please keep in mind there are exceptions and restrictions to SB 9 that need to be fully understood.
Other Highlights
Assembly Bill 68 allows landlords and homeowners to add 2 more units – an ADU and a Junior Accessory Dwelling Unit (JADU) – on any residential lot. This means you can legally create a triplex on every single lot (if your lot meets size and setback requirements) according to the 2024 ADU laws in California.
Additional units can be added to existing multi-family buildings like apartment complexes. Building owners can convert any non-habitable rooms, like attics, basements, garages, etc. into legal additional units.
Under AB 68, municipalities will be required to approve the following:
Single Family Homes:
One ADU (up to 1,200 sq. ft.) and one Junior ADU (a unit of not more than 500 sq. ft. and contained entirely within an existing single-family structure) per lot.
One detached ADU (up to 1,200 sq. ft.) that is new construction, existing structure, or the same footprint as the existing structure, along with one JADU.
Multifamily Dwellings
Multiple ADUs within existing multifamily structures.
Two detached ADUs on a multi-family lot.
Other Restrictions that are Prohibited by Local ADU Laws
To further remove barriers to the approval of ADU plans in California in 2024, various state laws still in effect prohibit local governments from imposing the following:
May not impose requirements on lot coverage or minimum lot size.
May not require replacement parking when a garage, carport, or covered parking structure is demolished to create an ADU or is converted to an ADU.
HOAs may not "prohibit or unreasonably restrict" the construction of ADUs on single-family residential lots.
Local agencies may not impose impact fees on ADUs under 750 sq. ft.
Interpreting the Law
Please note that this summary is based solely on the State Ordinance. Therefore, it is important to note that each City and County will release its own ADU rules and regulations in response to the new state laws. Some Cities and Counties may defer the effective date or challenge the state through legal channels in order to meet their own codes. Variations of these State rules will differ in each city and county.
Given the complexity of the new laws and the resulting City or County interpretations, it is even more critical that you consult a licensed architect who knows the in's and out's of the new 2024 ADU laws in California – and ADU In California is here for you!
5 things you must know about the ADU laws
CA wants you to build housing
California has a long way to go before solving our housing crisis but they also understand where to start. It's by allowing more housing to be built. Hence the new ADU updates.
Handbook updates are to further address barriers to the development of ADUs and JADUs. CA wants every city on board but plenty is not cooperating.
Based on the data CA acknowledges; "Shortage of affordable units and the units that are available can be out of reach for many people. To address our state’s needs, homeowners can construct an ADU on their lot or convert an underutilized part of their home into a JADU. This flexibility benefits both renters and homeowners who can receive extra monthly rent income. "
State law is one thing but local application of the law is another. HOA's cannot say NO to your ADU proposal. They may and will fight you on it but state law allows it.
Size does Matter
There's a difference between what you can do and what you should do. ADUs are meant to cost you sell than building an entirely brand new home from the ground up. In order to avoid most traditional impact fees the size of your ADU should be below 750 square feet. That's the sweet spot.
"ADUs converted from existing space and JADUs shall not be considered by a local agency, special district or water corporation to be a new residential use for purposes of calculating connection fees or capacity charges for utilities, unless constructed with a new single-family dwelling. The connection fee or capacity charge shall be proportionate to the burden of the proposed ADU, based on its square footage or plumbing fixtures as compared to the primary dwelling. State ADU law does not cover monthly charge fees."
Here is where to start to engage with local utility companies and engage with the city to get a full list of fees. 5 steps to take in order to get started on your ADU project.
Streamline Approval Process
Once a "completed" application is submitted, the local jurisdiction has 60 days to decision the permit application.
Every city is calling bluff on this one. Not many are enforcing or complying with the 60 day approval requirement. Some are using the covid excuse others are confident citizens won't fight back or challenge them.
Owner occupancy requirements
At some point you had to be living on site in order to qualify for the new ADU laws. But that is not the case anymore. Every California home can have up to 2 ADUs regardless of where the property owner actually lives.
Now some cities may fight you on it but as you can see there's a fight along each step of the ADU build-out process.
Legalizing existing non permitted ADUs
This might be the best law change to come out of the December 2020 ADU updates. Local agencies must delay enforcement against a qualifying substandard ADU for 5 years! As long as the Violation is not a health and safety issue. Get that ADU legalized.
Summary of Recent Changes to Accessory Dwelling Unit Laws
In Government Code Section 65852.150, theCalifornia Legislature found and declared that, among other things, allowing accessory dwelling units (ADUs) in zones that allow single-family and multifamily uses provides additional rental housing, and is an essential component in addressing California’s housing needs. Over the years, ADU law has been revised to improve its effectiveness at creating more housing units. Changes to ADU laws effective January 1, 2021, further reduce barriers, better streamline approval processes, and expand capacity to accommodate the development of ADUs and junior accessory dwelling units (JADUs).
ADUs are a unique opportunity to address a variety of housing needs and provide affordable housing options for family members, friends, students, the elderly, in-home health care providers, people with disabilities, and others. Further, ADUs offer an opportunity to maximize and integrate housing choices within existing neighborhoods.
Within this context, the California Department of Housing and Community Development (HCD) has prepared this guidance to assist local governments, homeowners, architects, and the general public in encouraging the development of ADUs. The following is a summary of recent legislation that amended ADU law: AB 3182 (2020) and SB 13, AB 68, AB 881, AB 587, AB 670, and AB 671 (2019). Please see Attachment 1 for the complete statutory changes for AB 3182 (2020) and SB 13, AB 68, AB 881, AB 587, AB 670, and AB 671 (2019).
AB 3182 (Ting)
Chapter 198, Statutes of 2020 builds upon recent changes to ADU law to further address barriers to the development and use of ADUs and JADUs.
This recent legislation, among other changes, addresses the following:
- States that an application for the creation of an ADU or JADU shall be deemed approved (not just subject to ministerial approval) if the local agency has not acted on the completed application within 60 days.
- Requires ministerial approval of an application for a building permit within a residential or mixed-use zone to create one ADU and one JADU per lot (not one or the other), within the proposed or existing singlefamily dwelling, if certain conditions are met.
- Provides for the rental or leasing of a separate interest ADU or JADU in a common interest development, notwithstanding governing documents that otherwise appear to prohibit renting or leasing of a unit, and without regard to the date of the governing documents.
- Provides for not less than 25 percent of the separate interest units within a common interest development be allowed as rental or leasable units
AB 68 (Ting), AB 881 (Bloom), and SB 13 (Wieckowski)
Chapter 653, Statutes of 2019 (Senate Bill 13, Section 3), Chapter 655, Statutes of 2019 (Assembly Bill 68, Section 2) and Chapter 659 (Assembly Bill 881, Section 1.5 and 2.5) build upon recent changes to ADU and JADU law and further address barriers to the development of ADUs and JADUs.
This legislation, among other changes, addresses the following:
- Prohibits local agencies from including in development standards for ADUs requirements on minimum lot size.
- Clarifies areas designated by local agencies for ADUs may be based on the adequacy of water and sewer services as well as impacts on traffic flow and public safety.
- Eliminates all owner-occupancy requirements by local agencies for ADUs approved between January 1, 2020, and January 1, 2025.
- Prohibits a local agency from establishing a maximum size of an ADU of less than 850 square feet, or 1,000 square feet if the ADU contains more than one bedroom and requires approval of a permit to build an ADU of up to 800 square feet.
- Clarifies that when ADUs are created through the conversion of a garage, carport or covered parking structure, replacement of offstreet parking spaces cannot be required by the local agency.
- Reduces the maximum ADU and JADU application review time from 120 days to 60 days.
- Clarifies that “public transit” includes various means of transportation that charge set fees, run on fixed routes and are available to the public.
- Establishes impact fee exemptions and limitations based on the size of the ADU. ADUs up to 750 square feet are exempt from impact fees; ADUs that are 750 square feet or larger may be charged impact fees but only such fees that are proportional in size (by square foot) to those for the primary dwelling unit.
- Defines an “accessory structure” to mean a structure that is accessory or incidental to a dwelling on the same lot as the ADU.
- Authorizes HCD to notify the local agency if HCD finds that their ADU ordinance is not in compliance with state law.
- Clarifies that a local agency may identify an ADU or JADU as an adequate site to satisfy Regional Housing Needs Allocation (RHNA) housing needs.
- Permits JADUs even where a local agency has not adopted an ordinance expressly authorizing them.
- Allows a permitted JADU to be constructed within the walls of the proposed or existing single-family residence and eliminates the required inclusion of an existing bedroom or an interior entry into the singlefamily residence.
- Requires, upon application and approval, a local agency to delay enforcement against a qualifying substandard ADU for five (5) years to allow the owner to correct the violation, so long as the violation is not a health and safety issue, as determined by the enforcement agency.
AB 587 (Friedman), AB 670 (Friedman), and AB 671 (Friedman)
In addition to the legislation listed above, AB 587 (Chapter 657, Statutes of 2019), AB 670 (Chapter 178, Statutes of 2019), and AB 671 (Chapter 658, Statutes of 2019) also have an impact on state ADU law, particularly through Health and Safety Code Section 17980.12.
These pieces of legislation, among other changes, address the following:
- AB 587 creates a narrow exemption to the prohibition for ADUs to be sold or otherwise conveyed separately from the primary dwelling by allowing deed-restricted sales to occur if the local agency adopts an ordinance. To qualify, the primary dwelling and the ADU are to be built by a qualified nonprofit corporation whose mission is to provide units to low-income households.
- AB 670 provides that covenants, conditions and restrictions (CC&Rs) that either effectively prohibit or unreasonably restrict the construction or use of an ADU or JADU on a lot zoned for single-family residential use are void and unenforceable (Civ, Code, § 4751).
- AB 671 requires local agencies’ housing elements to include a plan that incentivizes and promotes the creation of ADUs that can offer affordable rents for very low, low-, or moderate-income households and requires HCD to develop a list of state grants and financial incentives in connection with the planning, construction and operation of affordable ADUs.