The purpose of this chapter is to establish the procedures and development standards for the ministerial, non-discretionary processing of applications for new accessory dwelling units ("ADUs") and junior accessory dwelling units ("JADUs") in compliance with California Government Code Sections 66310 through 66342 and consistent with the policies, goals and programs of the Housing Element of the General Plan. ADUs and JADUs increase the overall supply of housing within established residential neighborhoods or as part of new residential subdivisions. Such units are intended to increase the supply of smaller, more affordable housing within existing residential neighborhoods and provide independent living units for prospective and current residents, including family members, students, local employees, the elderly, in-home health and childcare providers, and single adults, among others.

The intent of the Town in adopting the code section is to ensure that the Town's ordinance has the effect of providing for the creation of ADUs and JADUs and that the provisions in this chapter relating to matters including size, parking, and other development standards are not arbitrary, excessive, or burdensome so as to unreasonably restrict the ability of homeowners to create ADUs or JADUs consistent with state law intended to promote their development.

(Ord. No. 1043, § 5, 12-17-2024)

"Accessory dwelling unit" or "ADU" shall have the same meaning as provided in California Government Code Section 66313, as amended from time to time.

"Accessory dwelling unit—attached" means an accessory dwelling unit that is constructed as a physical expansion (i.e. addition) of the primary dwelling unit and shares a common wall with the primary dwelling unit.

"Accessory dwelling unit—detached" means an accessory dwelling unit that is constructed as a separate structure from the primary dwelling unit.

"Accessory dwelling unit—interior" means an accessory dwelling unit that is created within an existing structure as defined in this chapter.

"Efficiency unit" shall have the same meaning as provided in California Government Code Section 66313, as amended from time to time.

"Efficiency kitchen" shall mean an area in a unit that conforms to California Government Code Section 66333(f), as amended from time to time.

"Existing structure" means an existing permitted or otherwise legal single-family residence, including all fully enclosed areas such as a partial basement, an attached garage, or an accessory structure that can be made safety habitable under building codes.

"Junior accessory dwelling unit" or "JADU" shall have the same meaning as provided in California Government Code Section 66313, as amended from time to time.

"Kitchen" means a room or portion thereof containing permanent facilities designed and used for food preparation, cooking, eating and dish washing. A kitchen shall include all of the following: a sink with hot and cold running water; a stove-top/cook-top or an oven; a refrigerator; and built-in dish and utensil storage spaces. In addition to the aforementioned improvements, a kitchen may also include any of the following: microwave, convection oven, hot plate or automatic dishwasher.

"Livable space" shall have the same meaning as provided in California Government Code Section 66313, as amended from time to time.

"Living area" shall have the same meaning as provided in California Government Code Section 66313, as amended from time to time.

"Local agency" shall have the same meaning as provided in California Government Code Section 66313, as amended from time to time.

"Nonconforming zoning condition" shall have the same meaning as provided in California Government Code Section 66313, as amended from time to time.

"Passageway" shall have the same meaning as provided in California Government Code Section 66313, as amended from time to time.

"Proposed dwelling" shall have the same meaning as provided in California Government Code Section 66313, as amended from time to time.

"Public transit" means a location, including but not limited to, a bus stop or train station, where the public may access buses, trains, and other forms of transportation that charge set fares, run on fixed routes, and are available to the public. Public transit does not include school bus stops associated with bus routes operated seasonally or only during school hours for the intended purpose of serving students, even if the general public may access such bus service; or school bus routes provided by a school district for the exclusive use of students.

"Statewide Exemption ADU" shall mean an ADU that meets the criteria of California Government Code Section 66323(a).

"Statewide Exemption JADU" shall mean a JADU that meets the criteria of California Government Code Section 66323(a).

"Tandem parking" shall have the same meaning as provided in California Government Code Section 66313, as amended from time to time.

(Ord. No. 1043, § 5, 12-17-2024)

An ADU permit is required for the creation of an ADU unless it meets any of the criteria listed below:

(a)

The ADU is created from an existing structure as defined in Section 18.31.020 above or increases the gross floor area of an existing accessory structure by no more than twenty percent or one hundred and fifty square feet, whichever is greater.

(b)

The ADU or JADU meets the Statewide Exemption criteria listed in Government Code Section 66323.

(c)

The ADU is attached to the primary dwelling unit and has a floor area no greater than eight hundred square feet, maintains a minimum four foot side yard and rear yard setback, and any newly constructed square footage shall have a maximum height of sixteen feet.

(d)

The ADU(s) is located within the portions of existing multifamily dwelling 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. This subparagraph shall apply to projects for multiple ADUs, up to twenty-five percent of the existing multifamily units.

(e)

The ADU(s) is located on a parcel with an existing multifamily building. Multiple accessory dwelling units, not to exceed the number specified in clause (1) or (2), as applicable, that are located on a lot that has an existing or proposed multifamily dwelling, but are detached from that multifamily dwelling and are subject to a height limitation in Subparagraph (A), (B), or (C) of Paragraph (4) of Subdivision (b) of Section 66321, as applicable, and rear yard and side setbacks of no more than four feet.

(1)

On a lot with an existing multifamily dwelling, not more than eight detached accessory dwelling units. However, the number of accessory dwelling units allowable pursuant to this clause shall not exceed the number of existing units on the lot.

(2)

On a lot with a proposed multifamily dwelling, not more than two detached accessory dwelling units.

(f)

An ADU that meets the criteria of Subsections (a), (b), (d) or (e) of this section shall not be required to comply with any other development standards, except as explicitly allowed by state law.

(g)

This section shall not apply to units subject to Section 18.31.120.

The above-described ADUs shall comply with Section 18.31.050 regarding submittal of a building permit application and an Accessory Dwelling Unit Checklist.

(Ord. No. 1043, § 5, 12-17-2024)

For all ADU permits, an application shall be submitted to the Planning Division on prescribed forms that demonstrate that the ADU complies with the requirements contained in this chapter.

(Ord. No. 1043, § 5, 12-17-2024)

(a)

The Community Development Director or his/her designee shall issue an ADU permit as a ministerial permit. The application shall be processed within the timelines established by California Government Code Section 66317(a) as they may be amended from time to time. In addition to an ADU permit, the applicant shall also be required to obtain a building permit prior to the construction of the ADU.

(b)

Denial of Permit.

(1)

If the Town denies an application for an ADU or JADU, the Community Development Department shall within sixty-days return in writing a full set of comments to the applicant with a list of defective or deficient items and a description of how the applicant can remedy the defective or deficient items.

(2)

The Community Development Department shall not deny an application for an ADU that was previously unpermitted, but constructed before January 1, 2020 on the basis that (a) the ADU violates the 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 or (b) the ADU does not comply with Government Code Sections 66314-66322 or this Ordinance.

(A)

Notwithstanding Subsection 18.31.040(b)(2), the Town may deny an ADU or JADU permit that otherwise meets the criteria of that subsection if the Building Official finds that correcting the violation is necessary to protect the health and safety of the public or the occupants of the structure.

(B)

Section 18.31.040(b)(2) shall not apply to a structure that is deemed substandard pursuant to Section 17920.3 of the Health and Safety Code.

(C)

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 66324.

(D)

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.

(c)

This section shall not apply to units subject to Section 18.31.120.

(Ord. No. 1043, § 5, 12-17-2024)

A courtesy notice that includes a description of the project shall be provided for all ADUs requiring an ADU permit at least ten days prior to a decision by the Community Development Director. The notice shall be mailed to all owners within three hundred feet of the project site. No public hearing shall be required.

(Ord. No. 1043, § 5, 12-17-2024)

(a)

An ADU not requiring an ADU permit and a JADU shall meet all of the following conditions:

(1)

The unit is located on a parcel that permits residential uses.

(2)

The unit has an exterior access independent from the existing residence. Access from the public right-of-way to the unit may be provided through the front yard, side yard or rear yard of the primary residence.

(b)

For any Statewide Exemption ADU, Statewide Exemption JADU, or other unit not requiring an ADU permit, an applicant may submit a building permit application directly to the Building Division. An Accessory Dwelling Unit Checklist or Junior Accessory Dwelling Unit Checklist on the Town form shall be submitted to the Planning Division at the same time of building permit submittal to ensure that the above requirements are met.

(c)

This section shall not apply to units subject to Section 18.31.120.

(Ord. No. 1043, § 5, 12-17-2024)

(a)

All JADUs require a recorded deed restriction running with the land and binding on all future owners. The deed restriction shall be in a form approved by the Town Attorney and the property owner must record it in the official records of Marin County, California.

(b)

The deed restriction shall contain the following provisions:

(1)

The JADU shall not be sold separately from the main residence.

(2)

The JADUs size and attributes shall be maintained in compliance with Sections 66333 to 66399.

(c)

The property owner shall submit proof that the deed restriction has been recorded to the Planning Division prior to issuance of a building permit.

(Ord. No. 1043, § 5, 12-17-2024)

All ADUs/JADUs shall be subject to the following standards:

(a)

Allowable units on residential lots with a proposed or existing single-family dwelling:

(1)

One ADU may be constructed within an existing or proposed single-family dwelling or within an accessory structure, except as limited by Section 18.18.405(3)(J); and

(2)

One JADU may be constructed within an existing or proposed single-family dwelling, except as limited by Section 18.18.405(3)(J); and

(3)

One detached, new construction, ADU consistent with Section 18.31.080, except as limited by Section 18.18.405(3)(J). The detached, new construction, ADU may be in addition to an ADU and JADU described in Section 18.31.070(a)(1) and (2) above.

(b)

ADU(s) shall be allowed on a parcel with an existing multifamily dwelling consistent with state law except as limited by Section 18.18.405(3)(J).

(c)

Owner Occupancy.

(1)

Owner Occupancy (ADU)—owner occupancy is not required for either the primary residence or the ADU.

(2)

Owner Occupancy (JADU)—owner occupancy is required for either the JADU or the remaining portion of the single-family residence.

(d)

Street addresses shall be assigned to all ADUs to assist emergency responders. Address creation for a JADU may be required depending on the configuration of the unit, and subject to the Fire Marshal's recommendation.

(e)

The ADU/JADU shall not be sold independently of the primary dwelling on the parcel, except as explicitly allowed by California Government Code Section 66341.

(f)

No ADU shall be rented for less than thirty consecutive days.

(g)

Adequate Services. The proposed method of water supply and sewage disposal for the ADU/JADU must be provided, as well as service availability from any associated electric and gas provider for the lot. Letters of service availability must be provided by the appropriate utilities service provider(s) for the lot. The property owner must also demonstrate existing or future legal access to these utilities.

(Ord. No. 1043, § 5, 12-17-2024)

(a)

Separate Entry, Kitchen and Bathroom. All ADUs shall contain a separate entrance, kitchen and bathroom independent of the primary residence.

(b)

Zoning Conformance. All ADUs other than Statewide Exemption ADUs shall meet all development standards of the Zoning District in which it is located except as modified by this section.

(c)

Location. Detached ADUs other than Statewide Exemption ADUs shall be separated from the primary dwelling and any accessory structures by a minimum of three feet.

(d)

Setbacks.

(1)

Except as otherwise provided in this chapter, an ADU shall have side and rear yard setbacks of at least four feet.

(2)

The required rear yard setback for an ADU larger than eight hundred square feet on a lot zoned R-1-A, R-1-B, or R-1-C may be reduced to twenty-five feet if the lot is one acre or larger in size.

(3)

A front yard setback is not required if the property owner demonstrates that the normally applicable setback would preclude construction of an eight hundred square foot ADU with a four-foot side and rear yard setback. Upon said demonstration, the Town will reduce the front yard setback as needed to accommodate said ADU.

(4)

No setback shall be required for an existing living area or accessory structure that is fully or partially converted to an ADU, or for a structure constructed in the same location and to the same dimensions as an existing living area or accessory structure that is fully or partially converted to an ADU.

(e)

Height. Whenever an ADU is a portion of another structure, its height shall be measured from the base of that structure. ADUs shall be subject to all of the following requirements related to height.

(1)

Except as provided in Subsections (2)-(6) of this section, a detached ADU shall not exceed sixteen feet in height as measured in conformance with Section 18.04.335—Height, building or structure.

(2)

Detached ADUs on a lot with an existing or proposed single-family or multifamily dwelling unit shall not exceed eighteen feet in height, if the dwelling unit is within one-half mile walking distance of a major transit stop or a high-quality transit corridor, as those terms are defined in California Public Resources Code Section 21155. Such units are allowed an additional two feet in height to accommodate a roof pitch on the accessory dwelling unit that is aligned with the roof pitch of the primary dwelling unit.

(3)

A detached ADU on a lot with an existing or proposed multifamily, multistory dwelling shall not exceed eighteen feet in height.

(4)

If the detached ADU is in the flood plain and required to be elevated by federal, state, or local law, the unit may exceed sixteen feet in height only to the extent necessary to accommodate the required elevation and only up to a maximum of twenty feet. Such units are required to increase rear and side yard setbacks by one foot for every additional foot allowed under this subsection.

(5)

An attached ADU shall not exceed twenty-five feet in height, or the height limit that applies to the primary dwelling, whichever is lower. Notwithstanding the prior sentence, an accessory dwelling unit may not exceed two stories.

(6)

An ADU located above a detached garage shall not exceed twenty-five feet in height. Such units are required to meet the setback requirements of the underlying zoning district.

(f)

Size. ADUs shall be subject to all of the following requirements related to size.

(1)

Except as provided in Subsection (2) below, ADUs shall be limited to the following maximum sizes:

(2)

ADUs may exceed the maximum unit sizes provided in Subsection (1) above following approval of a discretionary Design Review application by the Planning Commission. In no case shall an ADU exceed one thousand two hundred square feet of gross floor area.

(3)

The gross floor area of attached or interior ADUs shall not exceed fifty percent of the existing living area (as defined in California Government Code Section 66313, as amended from time to time) of the primary residence. Notwithstanding the prior sentence, an attached or interior ADU may contain at least the maximum size set forth in Section 18.31.080(f)(1).

(4)

The minimum allowable gross floor area of an ADU shall be the minimum size permitted by the Building Code at the time of application, but in no case shall it preclude a minimum sized efficiency unit.

(5)

The square footage of a new detached garage constructed to provide required parking for the ADU shall be included in the overall size of the ADU.

(g)

Floodplain. An attached or detached ADU located in a floodplain shall comply with Title 16 of the CMMC.

(h)

Permits from Other Agencies. As part of the application for an ADU permit or building permit, the applicant shall provide approved permits from the appropriate agency(cies) or written statements that a permit is not required from the local, state or federal agencies with jurisdictions over construction activities at the project site.

(i)

Fire Sprinklers. Accessory dwelling units shall not be required to provide fire sprinklers if they are not required for the primary residence. The construction of an ADU shall not trigger any requirement for fire sprinklers to be installed in the existing primary dwelling unit or existing multifamily dwelling.

(j)

Modifications of Existing Multifamily Dwellings. If an existing multifamily dwelling has a rear or side setback of less than four feet, no modifications of the multifamily dwelling shall be required as a condition of approving the construction of an ADU.

(k)

Notwithstanding the above development standards, an attached or detached ADU may reduce the applicable rear yard or side yard setback requirements to four feet and may exceed applicable lot coverage and floor area ratio, pursuant to state law. The maximum allowable size of any ADU that exceeds standards related to lot coverage or floor area ratio, or reduces rear or side setback beyond otherwise applicable standards, is eight hundred square feet of gross floor area.

(Ord. No. 1043, § 5, 12-17-2024)

ADUs that do not qualify as a Statewide Exemption ADU shall be subject to the following additional development standards:

(a)

Lighting. All exterior lighting, including landscape lighting, must be dark sky compliant and/or have a BUG (Backlight, Uplight, Glare) rating of B3 or less, U0 for area lighting, U2 or less for all other outdoor lighting (including decorative luminaires), and G2 or less. All new exterior lighting must be designed and installed so that the filaments, light sources or lenses are shielded with opaque materials in such a way that they will not be visible at property lines. The exterior lights shall have a color temperature of 3500 Kelvin or lower (warm not cool).

(b)

Landscaping. Any tree over thirty inches in circumference removed in conjunction with the construction of an ADU must be replaced by a minimum twenty-four inch box tree on the project site, unless it is determined by the Fire Marshal that replacement planting is not consistent with current vegetation management standards.

(c)

Windows and Doors.

(1)

All new windows that face a side or rear yard adjoining a side or rear yard of an adjoining property and are located within fifteen feet of the shared property line shall be clerestory (minimum of six and five tenths feet above the finished floor height). This standard shall not apply if the structure on the adjoining property only has clerestory windows or solid doors on the elevation that faces the ADU.

(2)

All new doors that face a side or rear yard adjoining a side or rear yard of an adjoining property and are located within fifteen feet of the shared property line shall be solid. This standard shall not apply if the structure on the adjoining property only has clerestory windows or solid doors on the elevation that faces the ADU.

(3)

Non-clerestory windows or non-solid doors may be allowed on the building elevation that faces the side or rear yard adjoining a side or rear yard of an adjoining property located within fifteen feet of that shared property line following approval of a discretionary Design Review application by the Zoning Administrator, or with written approval from the adjoining property owner whose property faces the window(s) and/or doors.

For purposes of this Subsection (c), an adjoining property means a property that touches at some point the property with the ADU.

(d)

Balconies and decks. A balcony or deck constructed as part of an ADU shall comply with Section 18.24.050.

(e)

Grading. The site grading associated with the construction of an ADU, including associated site work, shall not exceed fifty percent of the volume of the structure. The volume of the structure shall not include area above the height of perimeter walls, such as the volume of attic space associated with a pitched roof.

(f)

Roof pitch. The roof pitch of an ADU constructed over an existing or proposed garage shall match the roof pitch of the existing or proposed residence.

(Ord. No. 1043, § 5, 12-17-2024)

JADUs are subject to the following objective standards.

(a)

Entryways. A JADU must include a separate entrance from the main entrance to the primary residence and may include an interior entry to the main living area. If an interior entry to the main living area is provided, the JADU may include a second interior doorway for sound attenuation.

(b)

Location. The JADU must be created within the walls of an existing or proposed single-family residence. Any enclosed uses within the residence, such as an attached garage, shall be considered as part of an existing residence.

(c)

Kitchen. The JADU shall include an efficiency kitchen as defined in California Government Code Section 66333(f).

(d)

Bathroom. A JADU may include separate sanitation facilities or may share sanitation facilities with the existing structure. If the JADU shares sanitation facilities with the existing structure, the JADU shall include an interior entry to the existing structure.

(e)

Size. The size of a JADU shall not exceed five hundred square feet of gross floor area. The gross floor area of a shared sanitation facility shall not be included in the maximum gross floor area of the unit.

(Ord. No. 1043, § 5, 12-17-2024)

(a)

Unless otherwise specified in Section (b) below, one on-site parking space in a location permitted pursuant to this chapter shall be required for an attached or detached ADU as defined in Section 18.31.020 above. This parking space is in addition to those spaces required for the primary residence.

(b)

On-site parking is not required for an ADU in any of the following instances:

(1)

The ADU is located within one-half mile walking distance of public transit as defined in Section 18.31.020 above.

(2)

The ADU is located within an architecturally and historically significant historic district.

(3)

The ADU is contained entirely within an existing structure as defined in Section 18.31.020 above.

(4)

When on-street parking permits are required but not offered to the occupant of the ADU.

(5)

When there is a car share vehicle located within one block of the ADU.

(6)

When a permit application for an ADU is submitted with a permit application to create a new single-family dwelling or new multifamily dwelling on the same parcel, provided that the accessory dwelling unit or the parcel satisfies any other criteria listed in this Paragraph (b).

(c)

The required parking space for the ADU may be located in any configuration on the same lot as the accessory dwelling unit, including, but not limited to, as covered spaces, uncovered spaces, or tandem spaces, or by the use of mechanical automobile parking lifts. The required parking space for the ADU may be located within the required front yard setback within the existing driveway or proposed expanded driveway or within the front setback between an existing driveway and the closest side property line.

(d)

When a garage, carport, covered or uncovered parking structure is demolished in conjunction with the construction of an ADU or is converted to an ADU, the space(s) eliminated from that structure are not required to be replaced elsewhere on the lot.

(Ord. No. 1043, § 5, 12-17-2024)

Sections 18.18.400—18.18.425 of the Municipal Code establishes limits on the number of ADUs and JADUs that can be created within portions of the Christmas Tree Hill Overlay District. These limitations are in place because of the public safety issues that arise related to fire hazards and evacuation routes due to the unique physical constraints on Christmas Tree Hill. The Central Marin Fire Department has advised that this neighborhood cannot safely accommodate increased density. The combined number of ADUs and JADUs in the ADU capacity districts of Christmas Tree Hill is limited to ten percent of the total number of primary residential units. The combined number of ADUs and JADUs in the ADU capacity zones in Christmas Tree Hill Overlay District shall not exceed the total number permitted by Sections 18.18.405(3)(J) and 18.18.410 of this title.

(Ord. No. 1043, § 5, 12-17-2024)

The decision of the Community Development Director granting or denying an ADU permit is a ministerial decision as required by state law, and shall not be subject to a public hearing. Following the decision of the Community Development Director, a request for a review of the record must be filed within ten calendar days of the date of the decision with the Town Clerk. Within ten calendar days after receipt of the request for review of the record, the Town Manager, or his/her designee, shall conduct a review of the record based on all documents submitted as part of the application and review process. For the purpose of calculating the ten days for review of the record, the request for review will be deemed to be received on the first day Town Hall is open to the public after receipt of the request. The ADU applicant and individual(s) filing for the review shall be notified in writing of the decision and such decision shall be final.

(Ord. No. 1043, § 5, 12-17-2024)

At his/her discretion, the Community Development Director or his/her designee may grant an owner's request to terminate an ADU/JADU. As a condition of termination, the Community Development Director or his/her designee shall require the owner to make modifications to the property to comply with current building code requirements, and remove the kitchen in the ADU/JADU. The property owner shall apply for a building permit to remove the kitchen as required by the Town's building and fire codes.

(Ord. No. 1043, § 5, 12-17-2024)