SB543 - Accessory dwelling units and junior accessory dwelling units.

Senate Bill No. 543 CHAPTER 520 An act to amend Sections 66311, 66313, 66317, 66320, 66321, 66323, and 66335 of, to amend and renumber Sections 66324, 66327, and 66332 of, and to add Sections 66333.5, 66335.5, and 66339.5 to, the Government Code, relating to land use. [ Approved by Governor October 10, 2025. Filed with Secretary of State October 10, 2025. ] LEGISLATIVE COUNSEL'S DIGEST SB 543, McNerney. Accessory dwelling units and junior accessory dwelling units. Existing law, the Planning and Zoning Law, among other things, provides for the creation by ordinance, or by ministerial approval if the local agency has not adopted an ordinance, of an accessory dwelling unit (ADU) or a junior accessory dwelling unit (JADU) in accordance with specified standards and conditions. Existing law defines the term “junior accessory dwelling unit” for these purposes to mean a unit that is no more than 500 square feet in size and contained entirely within a single-family structure. This bill would revise the definition of a “junior accessory dwelling unit” to require the size of a JADU to be no more than 500 square feet of interior livable space. Existing law makes certain declarations of the Legislature’s intent regarding the effect of an ADU ordinance. Existing law authorizes the Department of Housing and Community Development to review, adopt, amend, or repeal guidelines to implement uniform standards or criteria that supplement or clarify the terms, references, and standards for an ADU. This bill would revise the above-described declaration of legislative intent to additionally apply with respect to a JADU ordinance. The bill would also expand the department’s authority to review, adopt, amend, or repeal guidelines to additionally grant that authority with respect to terms, references, and standards for JADUs. Existing law requires a local agency to submit an ADU ordinance to the Department of Housing and Community Development within 60 days after the adoption for department review, as specified. Under existing law, the standards applicable to an ADU under these provisions supersede a conflicting local ordinance, except as specified. This bill would similarly require a local agency to submit a JADU ordinance to the department within 60 days after adoption for department review and would require the department to notify the local agency if the ordinance is noncompliant with JADU ordinance requirements, as specified. The bill would nullify and void that ordinance if the local agency fails to submit a copy of that ordinance or respond to the department’s findings that the ordinance is noncompliant, as specified. The bill would also specify that the standards applicable to a JADU supersede any conflicting local ordinance, except as specified. Existing law requires a local agency to consider ministerially a permit application for an ADU or a JADU within 60 days, as specified. If a local agency has not adopted an ADU ordinance, existing law requires a permit application for an ADU to be considered pursuant to this ministerial approval provision. Existing law prohibits a local ordinance, policy, or regulation, other than an ADU ordinance consistent with the laws governing approvals of ADUs, from being the basis for the delay or denial of a building permit or a use permit under this ministerial approval provision. If a local agency has not adopted a JADU ordinance, this bill would additionally require a permit application for a JADU to be considered pursuant to this ministerial approval provision, and would prohibit a local ordinance, policy, or regulation, other than a JADU ordinance consistent with the laws governing approvals of JADUs, from being the basis for the delay or denial of a building permit or a use permit under this ministerial approval provision. This bill would additionally require a permitting agency to determine whether an application for ADU or JADU is complete and provide written notice of the determination not later than 15 business days after the permitting agency received the application. If the permitting agency determines that an application is incomplete, the bill would require the permitting agency to provide the applicant with a list of incomplete items and a description of how the application can be made complete in the written notice and authorize the applicant to cure and address the application, as specified. The bill would require the permitting agency, if a permit application is determined to be incomplete or is denied, to provide a process for the applicant to appeal that decision, as provided, and would require the permitting agency to provide a final written determination by not later than 60 business days after receipt of the written appeal. Existing law imposes limits on construction, connection, and impact fees and capacity charges imposed on an ADU, including prohibiting impact fees upon the development of an ADU based on if the ADU is 750 square feet and requiring that any impact fee on an ADU of 750 square feet or more be charged proportionately in relation to the square footage of the primary dwelling unit. Existing law prohibits a local agency, special district, or water corporation from requiring the applicant to install a new or separate utility connection between an ADU and the utility or imposing a related connection fee or capacity charge for specified ADUs, except as specified. This bill would revise these provisions to additionally apply to construction, connection, and impact fees and capacity charges imposed on a JADU. The bill would revise the above-described limitation on impact fees to, instead, prohibit impact fees upon the development of an ADU that has 750 square feet of interior livable space or less or JADU that has 500 square feet of interior livable space or less, and to require that any impact fee on an ADU that has more than 750 square feet of interior livable space be charged proportionately in relation to the square footage of the primary dwelling unit. Existing law authorizes the governing board of a school district to levy a fee, charge, dedication, or other requirement against construction within the boundaries of the school district for the purpose of funding the construction or reconstruction of a school facility, subject to specified limitations. Under existing law, the fee, charge, dedication, or other requirement may only apply to specified constructions, including residential construction if the resulting assessable space exceeds 500 square feet. This bill would specify that an ADU or a JADU that contains less than 500 square feet of interior livable space does not increase assessable space by 500 square feet under these provisions. Existing law prohibits a local agency from establishing by ordinance a maximum square footage for an attached or detached ADU that is either less than 850 square feet or 1,000 square feet for an ADU that provides more than one bedroom. Existing law also prohibits a local agency from establishing by ordinance any requirement for a zoning clearance or separate zoning review or any other minimum or maximum size for an ADU, size based upon a percentage of the proposed or existing primary dwelling, or limits on lot coverage, floor area ratio, open space, front setbacks, and minimum lot size, for attached or detached dwellings that does not permit at least an 800-square foot ADU with four-foot side and rear yard setbacks. This bill would revise these size limitations to be based on the square feet of interior living space of the ADU. Existing law requires a local agency to ministerially approve a building permit application within a residential or mixed-use zone for specified ADUs or JADUs, including one detached, new construction, ADU that does not exceed 4-foot side and rear yard setbacks for a lot with a proposed or existing single-family dwelling. For these ADUs and JADUs, existing law authorizes a local agency to impose specified height limitations and total floor area limitations of no more than 800 square feet. Existing law prohibits a local agency from imposing a requirement that an ADU install a fire sprinkler if a sprinkler is not required for the primary residence. This bill would require a local agency to ministerially approve a building permit application for a combination of the specified ADUs or JADUs and revise the total area limitation to be based on the square feet of interior livable space. The bill would revise the prohibition on requiring fire sprinkler installation, as described above, to additionally apply to a JADU. This bill would make other technical and conforming changes to the provisions governing the review and approval of ADUs and JADUs. By imposing additional duties on local planning officials, this bill would impose a state-mandated local program. The California Constitution requires the state to reimburse local agencies and school districts for certain costs mandated by the state. Statutory provisions establish procedures for making that reimbursement. This bill would provide that no reimbursement is required by this act for a specified reason. Digest Key Vote: MAJORITY Appropriation: NO Fiscal Committee: YES Local Program: YES Bill Text The people of the State of California do enact as follows: SECTION 1. Section 66311 of the Government Code is amended to read: 66311. It is the intent of the Legislature that an accessory dwelling unit or a junior accessory dwelling unit ordinance adopted by a local agency has the effect of providing for the creation of accessory dwelling units or a junior accessory dwelling unit and that provisions in this ordinance relating to matters including unit size, parking, fees, and other requirements, are not so arbitrary, excessive, or burdensome so as to unreasonably restrict the ability of homeowners to create accessory dwelling units or junior accessory dwelling units in zones in which they are authorized by local ordinance. SEC. 2. Section 66313 of the Government Code is amended to read: 66313. For purposes of this chapter: (a) “Accessory dwelling unit” means an attached or a detached residential dwelling unit that provides complete independent living facilities for one or more persons and is located on a lot with a proposed or existing primary residence. It shall include permanent provisions for living, sleeping, eating, cooking, and sanitation on the same parcel as the single-family or multifamily dwelling is or will be situated. An accessory dwelling unit also includes the following: (1) An efficiency unit. (2) A manufactured home, as defined in Section 18007 of the Health and Safety Code. (b) “Accessory structure” means a structure that is accessory and incidental to a dwelling located on the same lot. (c) “Efficiency unit” has the same meaning as defined in Section 17958.1 of the Health and Safety Code. (d) “Junior accessory dwelling unit” means a unit that is no more than 500 square feet of interior livable space in size and contained entirely within a single-family residence. A junior accessory dwelling unit may include separate sanitation facilities, or may share sanitation facilities with the existing structure. (e) “Livable space” means a space in a dwelling intended for human habitation, including living, sleeping, eating, cooking, or sanitation. (f) “Living area” means the interior habitable area of a dwelling unit, including basements and attics, but does not include a garage or any accessory structure. (g) “Local agency” means a city, county, or city and county, whether general law or chartered. (h) “Nonconforming zoning condition” means a physical improvement on a property that does not conform to current zoning standards. (i) “Objective standards” means standards that involve no personal or subjective judgment by a public official and are uniformly verifiable by reference to an external and uniform benchmark or criterion available and knowable by both the development applicant or proponent and the public official prior to submittal. (j) “Passageway” means a pathway that is unobstructed clear to the sky and extends from a street to one entrance of the accessory dwelling unit. (k) “Permitting agency” means any entity that is involved in the review of a permit for an accessory dwelling unit or junior accessory dwelling unit and for which there is no substitute, including, but not limited to, applicable planning departments, building departments, utilities, and special districts. (l) “Proposed dwelling” means a dwelling that is the subject of a permit application and that meets the requirements for permitting. (m) “Public transit” means a location, including, but not limited to, a bus stop or train station, where the public may access buses, trains, subways, and other forms of transportation that charge set fares, run on fixed routes, and are available to the public. (n) “Tandem parking” means that two or more automobiles are parked on a driveway or in any other location on a lot, lined up behind one another. SEC. 3. Section 66317 of the Government Code is amended to read: 66317. (a) (1) A permit application for an accessory dwelling unit shall be considered and approved ministerially without discretionary review or a hearing, notwithstanding Section 65901 or 65906 or any local ordinance regulating the issuance of variances or special use permits. (2) (A) A permitting agency shall determine whether an application to create or serve an accessory dwelling unit is complete and provide written notice of this determination to the applicant not later than 15 business days after the permitting agency received the application. (B) If the permitting agency determines an application is incomplete, the permitting agency shall provide the applicant with a list of incomplete items and a description of how the application can be made complete. The list and description shall be provided with the written notice required by subparagraph (A). (C) After receiving a notice that the application was incomplete, an applicant may cure and address the items that are deemed to be incomplete by the permitting agency. (D) In the review of an application submitted pursuant to subparagraph (C), the permitting agency shall not require the application to include an item that was not included in the list required by subparagraph (B). (E) If an applicant submits an application pursuant to subparagraph (C), the permitting agency shall determine whether the additional application has remedied all incomplete items listed in the determination issued pursuant to subparagraph (B). This additional application is subject to the timelines and requirements specified in subparagraph (A). (F) If a permitting agency does not make a timely determination as required by this paragraph, the application or resubmitted application shall be deemed to be complete for the purposes of this section. (3) The permitting agency shall either approve or deny the application to create or serve an accessory dwelling u [Text truncated for display. Full text available on Congress.gov.]