Every California ADU Law, In Plain English.
A decade of legislation turned California into the easiest place in America to add a backyard home. Here are all 29 bills that did it, what each one changed, and a link to every official bill text. Wherever the law gets complicated, Abodu handles it for you.
File Your Ordinance With HCD, Or It's Void.
Renders local ADU ordinances null and void if the local agency fails to submit a copy to HCD within 60 days of adoption or fails to respond within 30 days to HCD findings of non-compliance. This enforcement mechanism ensures local jurisdictions cannot maintain ADU regulations that conflict with state law through inaction or delay.
Coastal ADUs Get A 60-Day Clock.
Requires local agencies with certified Local Coastal Programs to approve or deny coastal development permit applications for ADUs within 60 days, cutting previous coastal timelines by approximately 50%. The bill also eliminates appeals of ADU permits to the Coastal Commission and creates an exception allowing detached ADUs in disaster-affected areas to receive certificates of occupancy before the primary dwelling when the primary structure was substantially damaged by a declared emergency.
HCD Guidance Becomes Law: Clearer Standards.
Codifies existing HCD guidance on ADUs and JADUs, clarifies that floor area is measured as interior livable space excluding wall thickness and low-ceiling attics, and shortens application completeness review to 15 business days. The bill confirms the 60-day ministerial approval requirement, generally prohibits fees on ADUs under 750 square feet, and gives JADUs the same rules and protections as ADUs.
Lot Splits Expand Into More Neighborhoods.
Expands SB 9 by allowing lot splits and duplex development on single-family-zoned parcels to be approved ministerially in historic districts, provided the development does not alter or demolish existing historic structures. This removes a significant barrier that had prevented SB 9 utilization in many established California neighborhoods with historic designations.
JADU Owner-Occupancy Rules Loosened.
Narrows the owner-occupancy requirement for Junior ADUs to apply only when the JADU shares sanitation facilities (bathroom) with the single-family dwelling. JADUs with independent bathrooms are now exempt from owner-occupancy requirements, and the bill clarifies that all JADU rentals must be for terms longer than 30 days.
All ADU Law, One Chapter Of The Code.
Reorganizes all California ADU and JADU statutes into a dedicated chapter of the Government Code (Title 7, Division 1, Chapter 13), consolidating previously scattered provisions from sections 65852.2, 65852.22, 65852.23, and 65852.26. This urgency measure took immediate effect, providing attorneys, developers, and local agencies with a single consolidated reference for ADU law.
Clear Rules Coming For Coastal ADUs.
Requires the California Coastal Commission to coordinate with HCD to develop written guidance by July 1, 2026, for local governments to amend their Local Coastal Programs to clarify and simplify ADU permitting in the coastal zone. The bill mandates at least one public workshop for comments and aims to harmonize conflicting mandates between coastal regulations and state ADU law.
Small-Lot Housing On Vacant Parcels.
Expands SB 684 to allow ministerial subdivision and housing development on qualifying vacant parcels in single-family zones (maximum 1.5 acres, minimum 1,200 square foot parcels). The bill reduces the density requirement from 100% to 66% of maximum allowable density, clarifies that ADUs and JADUs do not count toward the 10-unit cap, and adds lot frontage to the list of exempt development standards.
Up To Eight ADUs On Multifamily Properties.
Significantly increases the number of detached ADUs permitted on existing multifamily properties from two to eight (or one per existing unit, whichever is less). The bill also prohibits local agencies from requiring replacement parking when any parking space, covered or uncovered, is demolished or converted to an ADU, and defines "livable space" for purposes of interior ADU conversions.
Amnesty For Unpermitted ADUs.
Addresses unpermitted ADUs or garage conversions built before January 1, 2020, requiring local building departments to allow legalization if units meet health and safety codes. Local agencies must provide owners with a checklist of substandard conditions requiring correction and are prohibited from charging penalties, impact fees, or connection fees for unpermitted ADUs that do not require new utility connections.
The State Now Polices Cities On ADU Law.
Expands HCD's enforcement authority to include state ADU laws, ADU amnesty provisions, and SB 9 lot split/duplex laws. The bill requires all California cities and municipalities to have a pre-approved ADU plan scheme in place by January 1, 2025, allowing homeowners to access standardized designs that comply with building and zoning codes.
Ten-Home Subdivisions, Approved Ministerially.
Requires local agencies to ministerially approve subdivisions of up to 10 parcels and housing developments of up to 10 units on qualifying multifamily-zoned lots of five acres or less. Projects are CEQA-exempt, require no public hearing or discretionary review, and parcels can be as small as 600 square feet. The bill exempts qualifying projects from HOA formation requirements under Davis-Stirling.
Owner-Occupancy Bans Are Gone For Good.
Permanently eliminates the sunset on owner-occupancy restrictions for ADUs, meaning local agencies cannot require property owners to live on-site to build or rent out an ADU for any permits issued after January 1, 2025. This makes permanent what had been a temporary prohibition under previous legislation, significantly expanding rental ADU investment potential.
Sell Your ADU As A Condo.
Authorizes local agencies to adopt ordinances allowing ADUs to be sold or conveyed as condominiums separately from the primary dwelling unit, subject to Department of Real Estate approval. Unlike previous separate conveyance laws limited to nonprofit-built units, this creates a pathway for any homeowner to sell their ADU as a standalone condominium if their local jurisdiction opts into the program.
Every City Must Offer Preapproved Plans.
Requires all local agencies to establish preapproval programs for ADU plans by January 1, 2025, accepting submissions from homeowners, architects, and developers. Once a plan is preapproved, local agencies must approve or deny ADU applications using that plan within 30 days, half the standard 60-day timeline, and must maintain a public website listing preapproved plans and vendor contact information.
Height Limits Raised To 18 Feet And Beyond.
Increases maximum height limits for detached ADUs to 18 feet within half a mile of major transit stops and 25 feet for attached ADUs. The bill prohibits denial of ADU permits due to nonconforming zoning conditions that do not affect health and safety, requires concurrent review of demolition permits for detached garages with ADU construction permits, and codifies that ADU construction does not trigger Group R occupancy changes.
Setbacks Capped At Four Feet.
Prohibits local agencies from imposing setback requirements greater than four feet and requires permitting agencies to return detailed comments on proposed ADUs within 60 days with specific suggestions for approval. The bill defines "objective standards" that local agencies may impose and clarifies that attached garages can be converted to JADUs without requiring independent bathrooms.
Duplexes And Lot Splits On Single-Family Land.
Allows ministerial approval of two-unit housing developments (duplexes) on single-family-zoned parcels and permits urban lot splits creating two parcels of at least 1,200 square feet each. When combined, a property owner can achieve up to four units on what was previously a single-family lot. Owner-occupancy is required for three years on lot-split properties, and the bill excludes properties with tenant evictions within the past 15 years.
ADUs Can Be Sold Separately, Where Allowed.
Requires local agencies to allow ADUs to be sold or conveyed separately from the primary dwelling when built by a qualified nonprofit corporation, sold to a low-income buyer, and held in a tenancy in common agreement with 45-year affordability restrictions. This expanded on the permissive framework of AB 587 by making the separate conveyance provisions mandatory rather than optional for qualifying projects.
Impact Fees Slashed, Approvals Accelerated.
Eliminated owner-occupancy requirements for ADUs through 2025 (later made permanent by AB 976), significantly reduced impact fees for ADUs under 750 square feet, and required local agencies to delay code enforcement on unpermitted ADUs to allow legalization. The bill works in conjunction with AB 68 and AB 881 to form the core 2020 ADU reform package.
An ADU And A JADU On One Lot, Approved In 60 Days.
Allows property owners to build both an ADU and a Junior ADU (JADU) on a single residential lot, effectively enabling triplex configurations on single-family parcels. The bill requires local agencies to ministerially approve ADU applications within 60 days and prohibits cities from imposing minimum lot size requirements or replacement parking mandates when converting garages to ADUs.
Nonprofits Can Sell ADUs Separately.
Permits local agencies to adopt ordinances allowing ADUs to be sold separately from the primary residence when the property was built by a qualified nonprofit corporation and sold to a low-income buyer under a tenancy in common agreement. This created the first pathway for ADU homeownership in California, though adoption remained optional for local jurisdictions.
Your HOA Can't Ban Your ADU.
Invalidates any deed restriction, covenant, or similar HOA rule that prohibits or unreasonably restricts the construction of ADUs or JADUs on lots zoned for single-family residential use. The bill ensures that homeowners' associations cannot impose blanket bans on ADU development, though HOAs may still apply reasonable architectural and design standards.
Cities Must Actively Encourage ADUs.
Requires local governments to include a plan in their housing elements that incentivizes and promotes the creation of ADUs that can be offered at affordable rent for very-low, low, or moderate-income households. The bill directs HCD to develop a list of existing state grants and financial incentives for ADU construction and include that information in the HCD handbook.
No More Owner-Occupancy Requirements.
Works in conjunction with AB 68 to prohibit owner-occupancy requirements for ADUs permitted through 2025 and authorizes ADUs on lots with multifamily dwellings. The bill eliminates replacement parking requirements when garages are converted to ADUs and prohibits local agencies from imposing setback requirements exceeding four feet for converted structures.
The Bill That Started It All.
Paired with AB 2299 as the foundational ADU reform legislation, this bill required local governments to allow ADUs on most residential lots statewide. The bill eliminated parking requirements for ADUs within one mile of public transit and limited local government authority to impose discretionary restrictions on ADU development.
Cities Must Allow ADUs.
Full Stop.
Paired with SB 1069, this foundational bill required cities and counties to allow ADUs on most residential lots, preempting overly restrictive local zoning ordinances and permitting processes. The bill established the modern framework for California ADU law by limiting local agency authority to block ADU development through discretionary review.
Junior ADUs Are Born.
Created the framework for Junior ADUs (JADUs), defined as units no more than 500 square feet contained entirely within an existing single-family structure. JADUs may share sanitation facilities with the primary dwelling and do not require fire sprinklers if the primary dwelling is not required to have them.