Accessory dwelling units shall comply with the requirements of this section, where allowed by Division
2 (Zoning Districts and Allowable Land Uses).
A. Purpose. The provisions of this section are intended to set standards, in compliance with California Government Code Sections
66310,
66311, and
66312, for the development of accessory dwelling units so as to increase the supply of smaller and affordable housing while ensuring that such housing remains compatible with the existing neighborhood.
B. General requirements. An accessory dwelling unit:
1. May be located on any lot that allows a single-family or multifamily residential use and includes a proposed or existing dwelling.
2. Is not subject to the density requirements of the General Plan, but shall otherwise be consistent with the General Plan text and diagrams.
3. Shall not be allowed on, or adjacent to, real property that is listed in the California Register of Historic Places.
4. Shall not be used for rentals with terms of less than 30 days.
5. Shall not be sold or otherwise conveyed separate from the primary residence.
6. Shall be required to dedicate street right-of-way in accordance with Section
18-12.030 of the Santa Rosa City Code when the right-of-way is needed to support a circulation element identified in the General Plan or any associate specific plan, unless otherwise approved through a waiver process described in Section
18-12.050.
C. Permit requirements. An application for an accessory dwelling unit or junior accessory dwelling unit that complies with all applicable requirements of this Section shall be approved ministerially.
1. If the Department, together with utility providers and County Environmental Health when a septic system is utilized, has not approved or denied the completed application within 60 days, the application shall be deemed approved. If the Department denies an application for an accessory dwelling unit or junior accessory dwelling unit, it shall provide in writing a full set of comments to the applicant with a list of items that are defective or deficient and a description of how the application can be remedied by the applicant.
2. A permit shall not be denied due to the correction of nonconforming zoning conditions, building code violations, or unpermitted structures that do not present a threat to public health and safety and are not affected by the construction of the accessory dwelling unit.
3. A permit shall not be denied for an unpermitted accessory dwelling unit or junior accessory dwelling unit that was constructed before January 1, 2020, because, among other conditions, the unit is in violation of building standards or state or local standards applicable to accessory dwelling units, unless the Department finds that correcting the violation is necessary to protect the health and safety of the public or occupants of the structure as identified in Health and Safety Code Section
17920.3 (Substandard Buildings).
4. A demolition permit for a detached garage that is to be replaced with an accessory dwelling unit shall be reviewed with the application for the accessory dwelling unit and issued at the same time. The applicant is not required to provide written notice or post a placard for the demolition of a detached garage that is to be replaced with an accessory dwelling unit.
D. Accessory Dwelling Units—Application and processing requirements.
1. Step one—Submittal. The application for an accessory dwelling unit permit shall be submitted to the Department concurrent with an application for a building permit. In addition to the standard submittal requirements for a building permit, an application for an accessory dwelling unit permit shall include all of the following (except as noted below):
a. Plot plan. A plot plan, drawn to scale, showing the dimensions of the perimeter of the parcel proposed for the accessory dwelling unit; the location and dimensioned setbacks of all existing and proposed structures on the site and structures located within 50 feet of the site; all easements, building envelopes, and special requirements of the subdivision as shown on the Final Map and improvement plans, if any; and average slope calculations for the site.
b. Floor plan. A floor plan, drawn to scale, showing the dimensions of each room, and the resulting floor area. The use of each room shall be identified, and the size and location of all windows and doors shall be clearly shown.
c. Elevations. Architectural elevations of each side of the proposed structure showing all wall height dimensions, openings, exterior finishes (including siding and window materials), original and finish grades, paint color, and roof pitch. The color of the existing or proposed primary residence shall be included if necessary to demonstrate compliance with Subsection
E.6 or
E.14, below. Applications for accessory dwelling units which do not modify a building's exterior are not required to submit elevations per this Subsection
c.
2. Step two—Decision. The Department shall approve or deny an application for an accessory dwelling unit permit within 60 days of submittal of a complete application. The accessory dwelling unit permit shall be issued only if the proposed accessory dwelling unit complies with all applicable standards in this Section.
3. Utility connections and fees.
a. Except as provided in Subsection
D.3.b,
a separate new utility connection and payment of a connection fee or capacity charge pursuant to State law and City fee schedule will be required for any new accessory dwelling unit.
b. No new or separate utility connection or related connection fee or capacity charge will be required for accessory dwelling units that are internal conversions of existing space within a single-family residence or an accessory structure, or for accessory dwelling units that are 750 square feet or smaller. Any impact fee charged for an accessory dwelling unit of 750 square feet or more shall be charged proportionately in relation to square footage of the primary dwelling unit.
E. Accessory Development standards. An accessory dwelling unit permit shall be issued only if the unit complies with the following development standards:
1. General. No development standards shall be applied that would prohibit up to an 800 square foot accessory dwelling unit that is no more than 16 feet in height with four-foot side and four-foot rear setbacks to be constructed in compliance with all other local development standards.
2. Setbacks.
a. Single-family residential districts including single-family PD districts. An accessory dwelling unit shall comply with the following setback requirements:
(1) A new attached or detached 800 square foot accessory dwelling unit shall provide a minimum four-foot side and four-foot rear setback, and a front setback consistent with that of the primary dwelling unit in a standard zoning district, or the most similar zoning district in the case of a PD. An 800 square foot accessory dwelling unit that complies with all other development standards may be built within the front yard setback of a lot if it is otherwise physically infeasible to build an accessory dwelling unit on other areas of the lot while maintaining the minimum rear and side yard setbacks outlined in this Subsection. Side-corner setbacks shall be a minimum of eight feet.
b. Multifamily districts including multifamily PD districts. An accessory dwelling unit shall comply with the following setback requirements.
(1) A new attached or detached accessory dwelling unit shall provide a minimum four-foot side and four-foot rear setback, except when abutting an R-3 zoning district, in which case no minimum side or rear setback is required. The front setback shall be consistent with a primary dwelling unit in the applicable standard zoning district, or the most similar standard zoning district in the case of a PD. Side-corner setbacks shall be a minimum of eight feet.
(i) If the existing multifamily dwelling exceeds height requirements or has a rear or side setback of less than four feet, the Department shall not require modification of the existing multifamily dwelling as a condition of approving the application to construct an accessory dwelling unit.
c. No setback shall be required for an existing legally constructed living area, garage, or other accessory structure that is converted to an accessory dwelling unit with independent exterior access from an existing or proposed residence. A setback of five feet from the side and rear property lines is required for an accessory dwelling unit constructed above an existing legally constructed or proposed garage.
d. Any new attached accessory dwelling unit, detached accessory dwelling unit or expansion of the single-family dwelling to support the internal conversion for an accessory dwelling shall be designed to maintain appropriate setbacks, as described in Subsection
E.2.a and
b above, from the future width of any abutting public streets. Future street configurations shall be based on the widths, standards and right-of-way lines in the circulation element of the Santa Rosa General Plan, the City Street Design and Construction Standards, City street lists or specifically addressed in a resolution adopted by the City Council.
3. Maximum floor area.
a. New detached unit. No newly constructed detached accessory dwelling unit may contain habitable space in excess of 1,200 square feet.
(1) An automatic fire sprinkler system shall be installed throughout structures that exceed 1,200 square feet total floor area.
b. New attached unit. No newly constructed attached accessory dwelling unit may contain habitable space in excess of 50 percent of the existing residential square footage except that 850 square feet total floor area must be allowed for studio or one-bedroom ADUs, and 1,000 square feet total floor area must be allowed for more than one-bedroom ADUs.
(1) An automatic fire sprinkler system shall be installed throughout all buildings that undergo any combination of substantial remodel, addition or both that exceed 50 percent of the existing total floor area.
c. Internal conversion. An accessory dwelling unit created entirely by the internal conversion of an existing or proposed single-family dwelling shall not occupy more than 45 percent of the existing habitable space of the residence, excluding the garage, nor shall it exceed 1,200 square feet except that 850 square feet total floor area must be allowed for studio or one-bedroom ADUs, and 1,000 square feet total floor area must be allowed for more than one-bedroom ADUs. An accessory dwelling unit created entirely by the internal conversion of a detached accessory structure shall not exceed a maximum of 1,200 square feet.
(1) An automatic fire sprinkler system shall be installed throughout all buildings that undergo any combination of substantial remodel, addition or both that exceed 50 percent of the existing total floor area.
4. Height limit.
a. A one-story accessory dwelling unit shall not exceed a maximum height of 16 feet, except as follows:
(1) The Department shall allow an additional two feet in height (up to 18 feet) to accommodate a roof pitch on an accessory dwelling unit that is aligned with the roof pitch on the primary dwelling unit.
(2) A detached accessory dwelling unit on a lot with an existing or proposed single family or multi-family dwelling unit that is within one-half mile walking distance of a major transit stop or a high-quality transit corridor shall not exceed a height of 18 feet.
(3) A height of 18 feet is also permitted for a detached accessory dwelling unit on a lot with an existing or proposed multifamily, multistory dwelling. A height of 25 feet applies to an accessory dwelling unit that is attached to a primary dwelling. This provision does not require the Department to allow an accessory dwelling unit to exceed two stories.
b. A two-story accessory dwelling unit shall not exceed a maximum height of 27 feet. No accessory dwelling unit shall exceed 27 feet in height.
c. When an accessory dwelling unit is located above an existing or proposed garage, carport or other accessory structure, the entire combined structure shall not exceed 27 feet in height. No accessory dwelling unit shall exceed 27 feet in height.
5. Lot coverage. An accessory dwelling unit shall comply with the lot coverage requirements of the applicable zoning district or the most similar zoning district in the case of a PD, except as referenced in Subsection
E.1, above.
6. Architectural compatibility. Architectural compatibility between the accessory dwelling unit and primary dwelling unit shall be demonstrated by matching one or more of the following qualities of the accessory dwelling unit to the proposed or existing primary dwelling unit:
b. Siding material and style; or
7. Exterior entrance. An accessory dwelling unit must include a separate exterior entrance.
8. Privacy. A balcony, window or door of a second story accessory dwelling unit shall be designed to lessen privacy impacts to adjacent properties. Appropriate design techniques include obscured glazing, window placement above eye level, screening treatments, or locating balconies, windows and doors toward the existing on-site residence.
9. Residential development. A residential dwelling must already exist on the lot or shall be constructed on the lot in conjunction with the construction of the accessory dwelling unit.
10. Number per lot.
a. A maximum of one detached or attached accessory dwelling unit, one accessory dwelling unit within the proposed space of a single-family dwelling or existing space of a single-family dwelling or accessory structure, and one junior accessory dwelling unit shall be permitted on any single-family lot zoned for single-family uses.
b. The number of accessory dwelling units allowed within a multifamily dwelling are limited to not more than 25 percent of the existing number of multifamily dwelling units on the property, except that at least one accessory dwelling unit shall be allowed. These accessory dwelling units shall be allowed within the portions of 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.
c. No more than two detached or attached ADUs are permitted on any multifamily lot developed with an existing or a proposed multifamily dwelling.
d. No more than eight detached ADUs are permitted on any multifamily lot with an existing multifamily dwelling provided that the number of detached ADUs does not exceed the existing number of multifamily units on the lot.
e. A maximum of one ADU per lot is allowed when both provisions of Senate Bill 9 - Government Code Sections
65852.21 (Two-unit development) and
66411.7 (Urban lot split) are invoked, provided the two following requirements are met.
(1) The parcel is located outside of the City's Wildland Urban Interface (WUI).
(2) The street to access the parcel is at least 36 feet wide, with parking provided on both sides or at least 30 feet wide, with parking limited to one side of the street.
No ADUs are permitted on lots created and developed as allowed by SB 9 which do not meet requirements 1 and 2 above.
11. Parking. One off-street parking space is required for an accessory dwelling unit, except as set forth below. The off-street parking shall be permitted uncovered, compact, tandem and in setback areas, unless the review authority determines that tandem parking or parking within a setback is not feasible due to specific site or topographical or fire and life safety conditions. No off-street parking shall be required if one or more of the following circumstances exist:
a. The accessory dwelling unit is 750 square feet or less in area, or a studio unit.
b. The accessory dwelling unit is located within one-half mile walking distance of public transit.
c. The accessory dwelling unit is located within a historic preservation district.
d. The accessory dwelling unit is part of the existing primary residence or an existing accessory structure.
e. When on-street parking permits are required but not offered to the occupant of an accessory dwelling unit.
f. When there is a car share vehicle located within one block of the accessory dwelling unit.
g. When a permit application for an accessory dwelling unit is submitted with a permit application to create a new single-family dwelling or a new multi-family dwelling on the same lot.
h. To qualify for an exception, the applicant must provide supporting evidence, such as a map illustrating the location of the accessory dwelling unit and its proximity to a public transit stop or car share vehicle or its location within a historic preservation district, or proof of local parking permit requirements.
i. No replacement off-street parking spaces are required when an accessory dwelling unit is created through the conversion or demolition, of a garage, carport or covered parking structure or uncovered parking space.
j. The appointment, responsibilities, and other aspects of the Design Review and Preservation Board, which shall serve as the City of Santa Rosa's historic and cultural preservation review authority, hereafter referred to in this Chapter as the "DRPB," shall comply with Section
20-60.060 (Design Review and Preservation Board).
k. A detached accessory dwelling unit is permitted to include an attached garage.
12. Standards for proposed accessory structures attached to an existing or proposed accessory dwelling unit.
a. A proposed accessory structure with a floor area less than 50 percent of the accessory dwelling unit floor area:
(1) Shall be processed ministerially in conjunction with the accessory dwelling unit.
(2) Shall comply with the lot coverage and setback requirements of this section.
(3) Shall comply with the 16-foot height limit for an accessory structure as required by Zoning Code Section
20-42.030.
b. A proposed accessory structure with a floor area that exceeds 50 percent of the total floor area of the accessory dwelling unit:
(1) Is subject to any discretionary review required by this Zoning Code.
(2) Shall comply with lot coverage, height, and setback requirements for an accessory structure in the applicable standard zoning district or the most similar standard zoning district in the case of a PD.
(3) Shall comply with any applicable hillside and/or creekside setbacks.
13. Standards for hillside areas.
a. Applicability. The development standards outlined below shall apply to accessory dwelling unit development on that portion of a site with a slope of 10 percent or greater.
b. Development standards. An accessory dwelling unit exceeding the applicable maximum height for a one-story accessory dwelling unit indicated in Subsection
E.4.a, or 800 square feet, shall observe 15-foot setbacks from side and rear property lines. When a building site abuts another parcel with a difference in vertical elevation of three feet or more, the required side and/or rear yard shall be measured from the nearest toe or top of slope to the structure, whichever is closer. Accessory dwelling units that are 800 square feet or less, and which comply with the maximum height requirements for a one-story accessory dwelling unit as described in Subsection
E.4.a, shall provide a minimum four-foot side and four-foot rear setback, consistent with this Section.
14. Standards for Historic Preservation Districts.
a. Applicability. The requirements outlined below shall apply to new accessory dwelling units within the Historic (-H) Combining District.
b. Architectural Compatibility. Architectural compatibility between the accessory dwelling unit and primary dwelling unit shall be demonstrated by one of the following means:
(1) Matching each of the following qualities of the accessory dwelling unit to the proposed or existing primary dwelling unit:
(B) Siding material and pattern, and
(C) Architectural features; or
(2) Through the preparation of a historic resource survey by a qualified professional that concludes the proposed accessory dwelling unit will not negatively impact historic resources on the property, will be consistent with Secretary of the Interior Standards for Treatment of Historic Properties.
15. Standards for creekside development.
a. Applicability. The development standards outlined below shall apply to accessory dwelling unit development within the specified distances to waterways as indicated in Section
20-30.040 – Creekside Development.
b. Development standards. An accessory dwelling unit exceeding 16 feet in height, or 800 square feet, shall observe setbacks referenced in Section
20-30.040. Accessory dwelling units that are 800 square feet or less, and no greater than 16 feet in height, shall provide a minimum four-foot side and four-foot rear setback, consistent with this Section.
16. Fire sprinkler system. Accessory dwelling units shall not be required to provide fire sprinklers if they are not required for the primary residence. The construction of an accessory dwelling unit shall not trigger a requirement for fire sprinklers to be installed in an existing primary dwelling or an existing multifamily dwelling.
17. Ownership. The Department shall not impose an owner-occupant requirement on an accessory dwelling unit before January 1, 2025.
F. Junior accessory dwelling unit. The following provisions are intended to set standards, in compliance with
California Government Code Section 66333-66339, for the development of junior accessory dwelling units so as to increase the supply of smaller and affordable housing while ensuring that such housing remains compatible with the existing neighborhood. It is not the intent of this section to override lawful use restrictions as set forth in Conditions, Covenants and Restrictions.
1. General requirements. A junior accessory dwelling unit:
a. May be located on any lot that allows single-family or multifamily dwellings and that contains only one existing or proposed single-family detached dwelling. Only one junior accessory dwelling unit shall be permitted per parcel.
b. Is not subject to the density requirements of the General Plan, but shall otherwise be consistent with the General Plan text and diagrams.
c. Shall not be used for rentals with terms of less than 30 days.
d. A maximum of one JADU per lot is allowed when both provisions of Senate Bill 9 - Government Code Sections
65852.21 (Two-unit development) and
66411.7 (Urban lot split) are invoked, provided the two following requirements are met.
(1) The parcel is located outside of the City's Wildland Urban Interface (WUI).
(2) The street to access the parcel is at least 36 feet wide, with parking provided on both sides or at least 30 feet wide, with parking limited to one side of the street.
No JADUs are permitted on lots created and developed as allowed by SB 9 which do not meet requirements 1 and 2 above.
2. Permit requirements. An application for a junior accessory dwelling unit that complies with all applicable requirements of this section shall be approved ministerially.
3. Application and processing requirements.
a. Step one—Submittal. The application for a junior accessory dwelling unit permit shall be submitted to the Department concurrent with an application for a building permit. In addition to the standard submittal requirements for a building permit, an application for a junior accessory dwelling unit permit shall include all of the following:
(1) Plot plan. If any expansion of the foundation is required for a junior accessory dwelling unit, a plot plan, drawn to scale, showing the dimensions of the perimeter of the parcel proposed for the junior accessory dwelling unit; the location and dimensioned setbacks of all existing and proposed structures on the site and structures located within 50 feet of the site; all easements, building envelopes, and special requirements of the subdivision as shown on the Final Map and improvement plans, if any; and average slope calculations for the site.
(2) Floor plan. A floor plan, drawn to scale, showing the dimensions of each room, the area devoted to the junior accessory dwelling unit, and the resulting floor areas of the junior accessory dwelling unit and of the primary residence. The use of each room shall be identified, and the size and location of all windows and doors shall be clearly shown. The plan shall identify whether separate or shared sanitation facilities are proposed.
(3) Deed restrictions. Deed restrictions completed, signed and ready for recordation in compliance with Subsection
G.
b. Step two—Decision. The Department shall approve or deny an application for a junior accessory dwelling unit permit within 60 days of submittal of a complete application. A junior accessory dwelling unit permit shall be issued only if the proposed junior accessory dwelling unit complies with all applicable standards in this Section. A permit for a junior accessory dwelling unit shall not be denied due to the correction of nonconforming zoning conditions, building code violations, or unpermitted structures that do not present a threat to public health and safety and are not affected by the construction of the junior accessory dwelling unit.
c. Utility connection fees.
(1) No new or separate utility connection and no connection fee for water, sewer, or power is required for a junior accessory dwelling unit.
4. Development standards. A junior accessory dwelling unit permit shall be issued only if the unit complies with the following development standards:
a. Maximum floor area. The junior accessory dwelling unit shall not exceed 500 square feet in total floor area.
b. Existing development. The junior accessory dwelling unit shall be contained entirely within the existing walls of an existing or proposed single-family dwelling, which includes the walls of an attached garage. However, an additional 150 square feet is permitted to allow for a separate entrance into the unit.
c. Kitchen. The junior accessory dwelling unit must contain a kitchen with the following minimum criteria:
(1) A kitchen sink having a clear working space of not less than 30 inches in front;
(2) A cooking appliance having a clear working space of not less than 30 inches in front;
(3) A refrigeration facility having a clear working space of not less than 30 inches in front;
(4) A food preparation counter and storage cabinets that are of reasonable size in relation to the size of the junior accessory dwelling unit.
d. Sanitation. Bathroom facilities may be separate from or shared with the single-family dwelling. A separate bathroom facility shall be provided if the junior accessory dwelling unit does not include an interior entry into the primary residence.
e. Entrance. The junior accessory dwelling unit shall include an exterior entrance separate from the main entrance to the single-family dwelling. The junior accessory dwelling unit may include a second interior doorway for sound attenuation.
f. Parking. Off-street parking shall not be required for junior accessory dwelling units. No replacement off-street parking spaces are required when a junior accessory dwelling unit is created through the conversion or demolition, of an attached garage, carport or covered parking structure.
G. Deed restrictions. Prior to occupancy of a junior accessory dwelling unit, the property owner shall file with the County Recorder a deed restriction containing a reference to the deed under which the property was acquired by the owner and stating that:
1. The junior accessory dwelling unit shall not be sold separately from the single-family residence;
2. The junior accessory dwelling unit shall be considered legal only so long as either the primary residence or junior accessory dwelling unit is occupied by the owner of record of the property. Such owner-occupancy, however, shall not be required if the property owner is a governmental agency, land trust or non-profit housing organization;
3. The restrictions shall run with the land and be binding upon any successor in ownership of the property. Lack of compliance shall void the approval junior accessory dwelling unit and may result in legal action against the property owner;
4. The developer of a subdivision that includes junior accessory dwelling units shall record the deed restrictions required by this subsection prior to the recordation of the Final Map or Parcel Map. Each lot with a junior accessory dwelling unit shall remain unoccupied until the property transfers ownership, allowing for compliance with the recorded owner-occupancy restriction;
5. A junior accessory dwelling unit shall not exceed 500 square feet of total floor area and shall comply with the development standards in Subsection
F.
(Ord. 3677 § 1, 2004; Ord. 3711 § 1 Exh. A, 2005; Ord. 3968 §§ 15, 16, 2011; Ord. 2017-024 § 7; Ord. 2018-020 § 2; Ord. 2020-003 § 2; Ord. 2021-012 §§ 34, 35; Ord. 2023-003 §§ 2–6; Ord. 2025-001, 1/28/2025)