“Accessory dwelling unit” or “ADU” means, pursuant to California Government Code Section 66313(a), as amended from time to time, an attached or a detached residential dwelling unit which provides complete independent living facilities for one (1) 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 ADU also includes an efficiency unit, as defined in California Health and Safety Code Section 17958.1 and a manufactured home, as defined in California Health and Safety Code Section 18007. An ADU is not an “accessory structure” as defined by Larkspur Municipal Code Section 18.08.030.

“Attached” means, for purposes of this chapter only, sharing a common wall, having abutting walls, or being connected by an enclosed corridor of not more than five (5) feet in length for horizontal attachments. For vertical attachments, “attached” means sharing floor or ceiling assemblies. The following devices or ones similar in function shall not be considered as providing attachment: breezeways, lanais, covered porches, arbors, fences, screens, decks, walkways, or structures meeting only at their corners.

“By-right ADUs” and “by-right JADUs” mean one (1) of the four (4) delineated types of ADUs or JADUs that the City must permit pursuant to California Government Code Section 66323.

“Building Division” means the Building Division of the City of Larkspur.

“Certificate of occupancy” means a document issued by the Chief Building Official that certifies that a commercial space or newly constructed residential building has been inspected for compliance with the California Building Standards Code and local ordinances that govern construction and occupancy, pursuant to California Residential Code Section 11, as amended from time to time.

“City” means the City of Larkspur or the applicable department or division within the City of Larkspur.

“Efficiency kitchen” shall mean an area in a JADU that includes a cooking facility with appliances, a food preparation counter, a sink, and storage cabinets that are of a reasonable size in relation to the size of the JADU.

“High-quality transit corridor” means a corridor with fixed route bus service with service intervals no longer than fifteen (15) minutes during peak commute hours pursuant to California Public Resources Code Section 21155, as amended from time to time.

“Junior accessory dwelling unit” or “JADU” means, pursuant to California Government Code Section 66313(d), as amended from time to time, a unit that is no more than five hundred (500) square feet in size and is contained entirely within a single-family residence. A JADU may include a separate bathroom or may share a bathroom with the primary residence.

“Livable space” means a space in a dwelling intended for human habitation, including living, sleeping, eating, cooking, or sanitation.

“Living area” means, pursuant to California Government Code Section 66313(e) as amended from time to time, the interior habitable area of a dwelling unit, including basements and attics, but does not include a garage or any accessory structure.

“Major transit stop” means, pursuant to California Public Resources Code Section 21155, as amended from time to time, a site containing an existing rail or bus rapid transit station, a ferry terminal served by either a bus or rail transit service, the intersection of two (2) or more major bus routes with a frequency of service interval of twenty (20) minutes or less during the morning and afternoon peak commute periods, or major transit stops included in the Metropolitan Transportation Commission regional transportation plan.

“Ministerial” or “ministerially” means considered and approved without discretionary review or a hearing, pursuant to California Government Code Section 66317(a), as amended from time to time.

“Multifamily dwelling” is a structure with two (2) or more attached dwelling units, other than ADUs or JADUs, on a single lot. Multiple detached single-unit dwellings on the same lot are not considered multifamily dwellings for the purposes of this chapter.

“Nonconforming zoning condition” means a physical improvement on a property that does not conform with current zoning standards, pursuant to Government Code Section 66313(h), as amended from time to time.

“Owner” means the individual or entity that owns a majority (i.e., greater than fifty (50) percent) interest in the property. The owner of property owned in joint tenancy shall be any party named. The owner of property owned as a tenancy in common shall be any party named, unless ownership shares are specified, in which case the owner shall be the individual(s) with a majority interest.

“Passageway” means a pathway that is unobstructed clear to the sky and extends from a street to one (1) entrance of the ADU, pursuant to California Government Code Section 66313(j), as amended from time to time.

“Permitting agency” means any entity that is involved in the review of a permit for an ADU or JADU, and for which there is no substitute, including, but not limited to, the Larkspur Planning Division, Building Division, the fire permitting agency, and water, sewer, electric and gas utilities.

“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, pursuant to California Government Code Section 66313(m), as amended from time to time.

“Qualified buyer” means, pursuant to California Government Code Section 66340, as amended from time to time, persons and families of low or moderate income as defined in California Health and Safety Code Section 50093, as amended from time to time.

“Qualified nonprofit corporation” means a nonprofit corporation organized pursuant to Internal Revenue Code Section 501(c)(3) that has received a welfare exemption under California Revenue and Taxation Code Section 214.15 for properties intended to be sold to low-income families who participate in a special no-interest loan program, pursuant to California Government Code Section 66340(b), as amended from time to time.

“Single-family dwelling” means, for the purposes of this chapter, a single unit providing complete, independent living facilities for one (1) family, including permanent provisions for living, sleeping, eating, cooking, and sanitation, and existing as a separate interest of real property, such as a detached single-family dwelling or a townhouse.

“Substandard building” means any building, portion of a building, or premises where there are conditions that endanger the life, limb, health, property, safety, or welfare of the public or occupants pursuant to California Health and Safety Code Section 17920.3, as amended from time to time.

“Tandem parking” means parking spaces for two (2) or more automobiles on a driveway or in any other location on the lot, lined up behind one another, pursuant to California Government Code Section 66313(n), as amended from time to time. (Ord. 1090 § 5 (Exh. A), 2025; Ord. 1077 § 17, 2024; Ord. 1066 § 6 (Exh. A), 2023; Ord. 1045 § 2, 2020; Ord. 1044 § 3, 2020; Ord. 1038 § 1 (part), 2019)

A. An application for an ADU or JADU that complies with this chapter shall be submitted to the Building Division and shall be considered ministerially. Any associated demolition permit shall be reviewed concurrently.

B. Within thirty (30) calendar days of submittal, the City shall determine application completeness. If incomplete, the City shall issue a comprehensive written list of missing items, limited to those on the official submittal checklist.

C. If the application is complete and an existing dwelling is on the lot, the City shall approve or deny the application ministerially within sixty (60) days from the date the City received the complete application.

D. If the ADU or JADU application is submitted with a new single-family or multifamily dwelling application, the Building Division may delay approving or denying the ADU or JADU application until the permit application to create the new single-family or multifamily dwelling is approved or denied. However, the ADU or JADU application review remains ministerial.

E. An applicant may request a delay on their application for any reason. The sixty (60) day period to approve or deny the permit shall be tolled for the period of the delay.

F. A complete application is deemed approved if the City fails to approve or deny the application within sixty (60) days of receiving the complete application, unless delayed at the applicant’s request.

G. If the Building Division denies the ADU or JADU application, the Building Division shall provide the applicant written comments within the time periods described in this section with a complete list of items that are defective or deficient and a description of how the application can be remedied. A full set of comments includes all comments from all reviewers, from every permitting agency. Following a denial, a corrected application resets the sixty (60) day review period.

H. Applicants may submit corrected applications to the Building Division. The Building Division may charge a fee to process a resubmitted application.

I. The City shall not require the correction of primary dwelling unit building code violations, nonconforming zoning conditions, or unpermitted structures as a condition of ministerial ADU or JADU approval, unless necessary to protect health and safety.

J. Notwithstanding anything to the contrary in this Code, the issuance of a ministerial ADU permit is not appealable. (Ord. 1090 § 5 (Exh. A), 2025; Ord. 1077 § 18, 2024; Ord. 1066 § 6 (Exh. A), 2023; Ord. 1062 § 14, 2022; Ord. 1045 § 2, 2020; Ord. 1044 § 3, 2020; Ord. 1038 § 1 (part), 2019; Ord. 1030 § 2(12), 2018; Ord. 1012 § 5, 2016; Ord. 992 § 6, 2013; Ord. 921 § 4, 2003. Formerly 18.21.030, 18.23.030, 18.23.050)

A. ADUs and JADUs in Converted Space (Single-Family Lots).

B. Detached ADUs (Single-Family Lots). One (1) detached, new construction, ADU is allowed per lot, up to eight hundred (800) square feet, with four (4) foot side and rear yard setbacks for a lot with a proposed or existing single-family dwelling that does not already have a detached ADU. Height limits are sixteen (16), eighteen (18), or twenty (20) feet depending on conditions specified in Larkspur Municipal Code Section 18.23.060(F).

C. Converted ADUs (Multifamily Lots). ADUs may be created within the portions of existing multifamily structures that are not used as livable space, including, but not limited to, storage rooms, boiler rooms, passageways, attics, basements, or garages, if each unit complies with State building standards for dwellings. The City shall allow at least one (1) ADU within an existing multifamily dwelling and shall allow up to twenty-five (25) percent of the existing multifamily dwelling units.

D. Detached ADUs (Multifamily Lots). Up to two (2) detached ADUs are allowed on a lot that has a proposed multifamily dwelling, or up to eight (8) detached ADUs are allowed on a lot with an existing multifamily dwelling, not to exceed the number of existing units on the lot. These ADUs are subject to four (4) foot rear and side yard setbacks and height limits of sixteen (16), eighteen (18), or twenty (20) feet, depending on conditions specified in Larkspur Municipal Code Section 18.23.060(F). No modification of nonconforming setbacks shall be required as a condition of ADU application approval.

E. Standards for By-Right ADUs.

A. Number of Units.

B. Location. ADUs may be within, attached to, or detached from the primary dwelling and may be created by converting a garage, carport, covered parking structure, storage area or accessory structure.

C. Access. ADUs shall have separate, independent exterior access. Attached units shall meet building code fire separation requirements and may not have internal openings to the primary residence.

D. Kitchen Facility and Bathroom. ADUs shall have permanent provisions for cooking and sanitation separate from the primary dwelling unit that meet minimum requirements of the building code (Larkspur Municipal Code Title 15).

E. Setbacks.

F. Size Limits.

G. Height Limits.

H. Number of Stories. Maximum two (2) stories.

I. Parking Requirements.

J. Architectural Standards. ADUs shall be designed to comply with the following standards:

K. Minimum Lot Size. No minimum lot size required.

L. Building Code. ADUs shall comply with all applicable requirements of the adopted California building codes and Larkspur Municipal Code Title 15.

M. Permanent Foundation. A permanent foundation shall be required for an ADU and JADU.

N. Short-Term Rental Prohibited. Any rental of an ADU shall exceed thirty (30) days. JADU rentals shall exceed thirty (30) days when permitted by State law.

O. Separate Sale Prohibited. Except as provided in Larkspur Municipal Code Section 18.23.100, an ADU or JADU shall not be sold or otherwise conveyed separate from the primary residence (including creation of a stock cooperative or similar common interest ownership arrangement), but may be rented.

P. Fire Sprinklers. Fire sprinklers and other fire safety measures are not required in the ADU or JADU if they are not required in the primary dwelling unit. The construction of an ADU shall not trigger a requirement for fire sprinklers to be installed in an existing primary or multifamily dwelling.

Q. Street Address Required. Street addresses shall be assigned to all ADUs to assist in emergency response.

R. Business License Required. If the ADU or JADU is rented, the property owner shall comply with Larkspur Municipal Code Chapter 5.04, General Provisions.

S. Deed Restriction. Prior to the first City inspection of construction performed under an issued JADU permit, a deed restriction, approved by the Community Development Director, or their designee, shall be recorded with the Marin County Recorder’s office. The deed restriction shall run with the land and shall be binding upon any successor in ownership of the property. The deed restriction shall include the prohibition on the sale of the JADU separate from the sale of the single-family residence, the requirement for owner occupancy of the JADU or primary residence, and restrictions that ensure continued compliance with a restriction on the size and attributes of the JADU.

T. Fire and Life Protection. For purposes of any fire or life protection ordinance or regulation, a JADU shall not be considered a separate or new dwelling unit. The City shall apply any ordinance or regulation relating to fire and life protection requirements that applies uniformly to all single-family residences within the zone regardless of whether the single-family residence includes a JADU or not.

U. Termination of Use. To encourage the retention of affordable housing and rental housing units in the City, any modification of the ADU or JADU or termination of use shall require the issuance of a building permit and be subject to the then-applicable zoning and building codes. For example, if the kitchen, bathroom, and/or sleeping facilities of the ADU are removed and the structure no longer qualifies as an ADU or JADU, the structure may be required to provide additional off-street parking or comply with floor area, lot coverage or other development requirements.

V. Historic Preservation. An application for a new detached ADU or ADU that will be created by a building addition on property zoned H, any site within the Downtown Historic District, and any site that contains a historic resource listed on the Larkspur Historic Resources Inventory or eligible for listing on the Larkspur Historic Resources Inventory shall be accompanied by a report prepared by a professional that meets the minimum qualifications of a professional in the disciplines of Architectural History or Historical Architecture, as defined in the Secretary of the Interior’s Standards (36 CFR 61) that the ADU design complies with the Secretary of the Interior’s Standards for the Treatment of Historic Properties with Guidelines for Preserving, Rehabilitating, Restoring, and Reconstructing Historic Buildings or the Secretary of the Interior’s Standards for Rehabilitation and Guidelines for Rehabilitating Historic Buildings (1995), Weeks and Grimmer.

W. Passageways. No passageway shall be required in conjunction with the construction of an ADU. (Ord. 1090 § 5 (Exh. A), 2025; Ord. 1077 §§ 19 - 22, 2024; Ord. 1066 § 6 (Exh. A), 2023; Ord. 1062 § 14, 2022; Ord. 1045 § 2, 2020; Ord. 1044 § 3, 2020; Ord. 1038 § 1 (part), 2019; Ord. 1030 § 2(12), 2018; Ord. 1012 § 5, 2016; Ord. 953 § 1(28), 2007; Ord. 921 § 4, 2003. Formerly 18.21.040, 18.23.040)

A. Owner Occupancy. The owner shall reside in either the remaining portion of the primary residence or in the newly created JADU. Owner-occupancy shall not be required if the owner is another governmental agency, land trust, or housing organization.

B. JADU Development Standards.

A. Permit Required. A building permit is required to legalize any ADU or JADU constructed without permit prior to January 1, 2020. Applicants may first obtain a confidential third-party code inspection from a licensed contractor to determine the unit’s existing condition or potential scope of building improvements. Permit applications shall include the applicable fee and may be subject to a City inspection with tenant consent for compliance with health and safety standards.

Pursuant to California Government Code Section 66332, the City shall not deny a permit based on violations of building standards, State ADU Law, or local ordinances regulating ADUs and JADUs. A checklist of substandard building conditions shall be available on the City’s website.

If health and safety violations are found, the City shall issue permits necessary to correct them without penalizing the applicant, unless the Chief Building Official finds the violation poses a health or safety risk to the public or occupants of the structure, or if the building is deemed substandard under California Health and Safety Code Section 17920.3.

Nothing in this section limits the City’s authority to pursue enforcement or require corrective action.

B. Application to Delay Enforcement. Pursuant to California Health and Safety Code Section 17980.12, owners of ADUs built before January 1, 2020, who receive a notice to correct a building standard violation may request a delay of enforcement for up to five (5) years if the correction is not necessary for health and safety. Requests must be in writing to the Chief Building Official, who shall consult with the Central Marin Fire Department Chief. No delays shall be granted on or after January 1, 2030, but delays approved before that date remain valid through their full term. This subsection is repealed as of January 1, 2035. (Ord. 1090 § 5 (Exh. A), 2025)

A. Notwithstanding Larkspur Municipal Code Section 18.23.060(N), an ADU may be sold or conveyed separately from the primary residence to a qualified buyer upon receipt of a conditional use permit from the Community Development Director pursuant to California Government Code Section 66341. The City Council may establish a fee for the permit. The Community Development Director shall issue the permit upon receipt of evidence demonstrating the following requirements have been met: