Annotated California ADU Law Library

The Legislature finds and declares all of the following:

(a) Accessory dwelling units are a valuable form of housing in California.

(b) Accessory dwelling units provide housing for family members, students, the elderly, in-home health care providers, the disabled, and others, at below market prices within existing neighborhoods.

(c) Homeowners who create accessory dwelling units benefit from added income, and an increased sense of security.

(d) Allowing accessory dwelling units in single-family or multifamily residential zones provides additional rental housing stock in California.

(e) California faces a severe housing crisis.

(f) The state is falling far short of meeting current and future housing demand with serious consequences for the state’s economy, our ability to build green infill consistent with state greenhouse gas reduction goals, and the well-being of our citizens, particularly lower and middle-income earners.

(g) Accessory dwelling units offer lower cost housing to meet the needs of existing and future residents within existing neighborhoods, while respecting architectural character.

(h) Accessory dwelling units are, therefore, an essential component of California’s housing supply.

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.

(a) Fees charged for the construction of accessory dwelling units or junior accessory dwelling units shall be determined in accordance with Chapter 5 (commencing with Section 66000) and Chapter 7 (commencing with Section 66012).

(b) An accessory dwelling unit or junior accessory dwelling unit 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, including water and sewer service, unless the unit was constructed with a new single-family dwelling.

(c) (1) A local agency, special district, or water corporation shall not impose any impact fee upon the development of an accessory dwelling unit that has 750 square feet of interior livable space or less or a junior accessory dwelling unit that has 500 square feet of interior livable space or less. Any impact fees charged for an accessory dwelling unit that has more than 750 square feet of interior livable space shall be charged proportionately in relation to the square footage of the primary dwelling unit.

(2) For purposes of this subdivision, “impact fee” has the same meaning as the term “fee” is defined in subdivision (b) of Section 66000, except that it also includes fees specified in Section 66477. “Impact fee” does not include any connection fee or capacity charge charged by a local agency, special district, or water corporation.

(3) For the purposes of this section and Section 17620 of the Education Code, an accessory dwelling unit or junior accessory dwelling unit that contains less than 500 square feet of interior livable space shall, for the purpose of subparagraph (C) of paragraph (1) of subdivision (a) of Section 17620 of the Education Code, be considered other residential construction that does not increase assessable space by 500 square feet.

(d) For an accessory dwelling unit or a junior accessory dwelling unit described in paragraph (1) of subdivision (a) of Section 66323, a local agency, special district, or water corporation shall not require the applicant to install a new or separate utility connection directly between the unit and the utility or impose a related connection fee or capacity charge, unless the unit was constructed with a new single-family dwelling, or upon separate conveyance of the accessory dwelling unit pursuant to Section 66342.

(e) For an accessory dwelling unit that is not described in paragraph (1) of subdivision (a) of Section 66323, a local agency, special district, or water corporation may require a new or separate utility connection directly between the accessory dwelling unit and the utility. Consistent with Section 66013, the connection may be subject to a connection fee or capacity charge that shall be proportionate to the burden of the proposed accessory dwelling unit, based upon either its square feet or the number of its drainage fixture unit (DFU) values, as defined in the Uniform Plumbing Code adopted and published by the International Association of Plumbing and Mechanical Officials, upon the water or sewer system. This fee or charge shall not exceed the reasonable cost of providing this service.

(a) Notwithstanding any other law, and except as otherwise provided in subdivision (b), a local agency shall not deny a permit for an unpermitted accessory dwelling unit or an unpermitted junior accessory dwelling unit that was constructed before January 1, 2020, due to either of the following:

(1) The accessory dwelling unit or junior accessory dwelling unit is in violation of building standards pursuant to Article 1 (commencing with Section 17960) of Chapter 5 of Part 1.5 of Division 13 of the Health and Safety Code.

(2) The accessory dwelling unit or junior accessory dwelling unit does not comply with this article or Article 3 (commencing with Section 66333), as applicable, or any local ordinance regulating accessory dwelling units or junior accessory dwelling units.

(b) Notwithstanding subdivision (a), a local agency may deny a permit for an accessory dwelling unit or junior accessory dwelling unit subject to subdivision (a) if the local agency makes a finding that correcting the violation is necessary to comply with the standards specified in Section 17920.3 of the Health and Safety Code.

(c) This section shall not apply to a building that is deemed substandard pursuant to Section 17920.3 of the Health and Safety Code.

(d) A local agency shall inform the public about the provisions of this section through public information resources, including permit checklists and the local agency’s internet website, which shall include both of the following:

(1) A checklist of the conditions specified in Section 17920.3 of the Health and Safety Code that would deem a building substandard.

(2) Informing homeowners that, before submitting an application for a permit, the homeowner may obtain a confidential third-party code inspection from a licensed contractor to determine the unit’s existing condition or potential scope of building improvements before submitting an application for a permit.

(e) A homeowner applying for a permit for a previously unpermitted accessory dwelling unit or junior accessory dwelling unit constructed before January 1, 2020, shall not be required to pay impact fees or connection or capacity charges except when utility infrastructure is required to comply with Section 17920.3 of the Health and Safety Code and when the fee is authorized by subdivision (e) of Section 66311.5.

(f) Subject to subdivision (c), upon receiving an application to permit a previously unpermitted accessory dwelling unit or junior accessory dwelling unit constructed before January 1, 2020, an inspector from the local agency may inspect the unit for compliance with health and safety standards and provide recommendations to comply with health and safety standards necessary to obtain a permit. If the inspector finds noncompliance with health and safety standards, the local agency shall not penalize an applicant for having the unpermitted accessory dwelling unit or junior accessory dwelling unit and shall approve necessary permits to correct noncompliance with health and safety standards.

Notwithstanding Section 65803, this chapter shall also apply to a charter city.

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.

The department may review, adopt, amend, or repeal guidelines to implement uniform standards or criteria that supplement or clarify the terms, references, and standards set forth in this chapter. The guidelines adopted pursuant to this section are not subject to Chapter 3.5 (commencing with Section 11340) of Part 1 of Division 3 of Title 2.