San Bruno City Zoning Code
CHAPTER 12
90 ACCESSORY DWELLING UNITS AND JUNIOR ACCESSORY DWELLING UNITS
§ 12.90.010 Purpose.
The purpose of this chapter is to comply with California Government Code Sections 6314 through 66339 which provides standards for the development of accessory dwelling units and junior accessory dwelling units so as to increase the supply of smaller and affordable housing while ensuring that they remain compatible with existing neighborhoods. In cases of conflict between this chapter and any other provision of this title, the provisions of this chapter shall prevail. To the extent that any provision of this chapter is in conflict with state law, the applicable provision of state law shall control, but all other provisions of this chapter shall remain in full force and effect.
An accessory dwelling unit that conforms to this chapter shall be deemed to be a residential use that is consistent with the existing General Plan and zoning designations for the lot, and shall be deemed an accessory use, as defined in Section 12.80.015, and shall not be considered to exceed the allowable density for the lot upon which it is located. An accessory dwelling unit is not a recreational vehicle or an "excess housekeeping unit," as defined in Section 12.92.030 of the San Bruno zoning ordinance, unless verified by the planning division to be an accessory dwelling unit.
(Ord. 1898 § 3, 2021; Ord. 1958, 1/28/2025)
§ 12.90.020 Definitions.
an interior, attached or a detached residential dwelling unit located on a single lot with a proposed or existing single-family residence or existing multifamily residence which provides complete independent living facilities for one or more persons. It shall include permanent provisions for living, sleeping, eating, cooking, and sanitation on the same parcel as the single-family dwelling or multi-Family dwelling. At minimum, the kitchen shall contain a sink, refrigerator, and either a cooktop or range. An accessory dwelling unit also includes the following:
Efficiency unit, as defined in Section 17958.1 of Health and Safety Code: a separate living space for occupancy by no more than two persons, which has a minimum floor area of one hundred fifty square feet containing partial kitchen or bathroom facilities.
Manufactured home, as defined in Section 18007 of Health and Safety Code: a transportable structure which in the traveling mode is eight feet or more in width and forty feet or more in length and is a minimum of three hundred twenty square feet and which is built on a permanent chassis and is designed to be used as a dwelling with or without a permanent foundation when connected to the required utilities, and includes the plumbing, heating, air conditioning, and electrical systems contain therein.
a kitchen including all of the following: (1) a cooking facility with appliances; (2) a food preparation counter and storage cabinets that are of reasonable size in relation to the size of the junior accessory dwelling unit.
a residential unit that is no more than five hundred square feet in size and contained entirely within a single-family dwelling unit, including an attached garage. A junior accessory dwelling unit must contain an entrance separate from the entrance for the single-family dwelling and shall either include separate sanitation facilities (bathroom containing a sink, toilet, and shower/tub) or share sanitation facilities with the single-family dwelling. An efficiency kitchen is required, which must include a sink, a cooking facility with appliances (e.g., microwave, toaster oven, hot plate), as well as a food preparation counter and storage cabinets.
a space in a dwelling intended for human habitation, including living, sleeping, eating, cooking, or sanitation.
the interior habitable area of a dwelling unit, including basements and attics, but does not include a garage or any accessory structure.
a pathway that is unobstructed clear to the sky and extends from a street to one entrance of the accessory dwelling unit.
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.
two or more automobiles parked on a driveway or in any other location on a lot, lined up behind one another.
(Ord. 1898 § 3, 2021; Ord. 1958, 1/28/2025)
§ 12.90.030 General requirements.
A.
Zoning. Accessory dwelling units shall be a permitted use in any district where residential uses are permitted. Junior accessory dwelling units shall be permitted in the single-family zoning districts within an existing single-family residence, or as part of a proposed single-family residence.
B.
Junior Accessory Dwelling Units. Where permitted, one junior accessory dwelling unit may be developed on any legally created lot and shall be located within the walls of an existing or proposed single-Family residence. A junior accessory dwelling unit may be developed on the same lot as an accessory dwelling unit that meets the following standards:
C.
Accessory Dwelling Units.
1.
Multifamily Residential Structures. One of the following may be permitted on a lot with an existing multifamily residential structure:
a.
Up to twenty-five percent of the number of existing multifamily units in the building, but at least one unit, shall be allowed in existing multifamily dwelling structures within the portions of the structure that are not used as livable space, including, but not limited to, storage rooms, boiler rooms, passageways, attics, basements, or garages, provided that the unit complies with California Building Code Standards. An accessory dwelling unit shall not be created within any portion of an existing dwelling unit in a multifamily structure; or
b.
Multiple accessory dwelling units, as set forth in subparagraphs i or ii, shall be allowed on a lot with an existing multifamily residential structure, provided that the height of the detached accessory dwelling unit does not exceed sixteen feet and each unit has side yard and rear yard setbacks of at least four feet.
i.
On a lot with an existing multifamily dwelling, not more than eight detached accessory dwelling units shall be allowed. However, the number of accessory dwelling units allowable pursuant to this clause shall not exceed the number of existing units on the lot; or
ii.
On a lot with a proposed multifamily dwelling, not more than two detached accessory dwelling units shall be allowed.
2.
Single-Family Residences. One accessory dwelling unit is permitted per residential lot containing an existing or proposed single family residence. The accessory dwelling unit may be:
a.
Attached to an existing or proposed single-family residence;
b.
Located within the walls of the existing or proposed single-family residence, including all or a portion of an attached garage;
c.
Located within a legally-established existing accessory structure which may include an expansion of up to one hundred fifty square feet beyond the existing physical dimensions to accommodate ingress and egress only;
d.
Detached from the existing or proposed single-family residence, but located on the same lot;
e.
Located over a legally established detached garage.
D.
Aircraft Noise Insulation. Any accessory dwelling unit located in the 65 CNEL or higher areas, as shown on the Noise Compatibility Zones map of the Comprehensive Airport Land Use Compatibility Plan for the Environs of San Francisco Airport, is required to be designed to Aircraft Noise Insulation Program standards.
(Ord. 1898 § 3, 2021; Ord. 1958, 1/28/2025)
§ 12.90.040 Permitting procedures.
Within sixty days of receipt of a complete building permit application, the community development department staff shall ministerially process for approval any application for an ADU or JADU permit pursuant to this chapter. Incomplete applications will be returned with an explanation of what additional information is required. Upon finding that the ADU or JADU meets the requirements of this chapter, the application shall be approved ministerially without discretionary review or public hearing and the applicant may proceed to acquire a building permit. Review and approval of all ADUs and JADUs is ministerial, and CEQA does not apply to ministerial permits. Prior to obtaining a building permit for a JADU, submission of a completed, signed deed restriction is required, as described by Section 12.90.060.
§ 12.90.050 Development standards.
A.
General Requirements. Accessory dwelling units shall conform to the height, setbacks, lot coverage and any other development or supplemental standards of any applicable zoning district(s), the development standards below, other requirements of the Zoning Ordinance, and other applicable city codes. In any case of conflict between this section and any other part of the San Bruno Municipal Code, the standards specific to this section shall take precedence.
B.
Building and Fire Code Requirements. Junior accessory dwelling units and accessory dwelling units shall comply with all applicable building and fire code requirements, except fire sprinklers shall not be required in a junior accessory dwelling unit or accessory dwelling unit if they are not required for the primary residence.
C.
Entrances. A junior accessory dwelling unit and an accessory dwelling unit shall have a separate exterior entrance from the primary dwelling unit. Interior entries from the primary residence are allowed, but junior accessory dwelling units and accessory dwelling units must be separated and delineated from the main residence by a door.
D.
Junior Accessory Dwelling Units.
1.
Location. Junior accessory dwelling units shall be contained entirely within the walls of an existing or proposed single-family residence, and shall contain at least an efficiency kitchen equipped with a sink, a cooking facility with appliances (e.g., microwave, toaster oven, hot plate) as well as a food preparation counter and storage cabinets that are of reasonable size in relation to the junior accessory dwelling unit.
2.
Size. A junior accessory dwelling unit shall be no larger than five hundred square feet in size, and no junior accessory dwelling unit shall be smaller than the size required to allow an efficiency unit pursuant to Health and Safety Code Section 17958.1.
3.
Sanitation Facilities. A junior accessory dwelling unit may, but is not required to, include separate sanitation facilities. If separate sanitation facilities are not provided, the junior accessory dwelling unit shall share sanitation facilities with the single-family residence and shall have an interior access to any shared sanitation facilities.
4.
Balconies and Openings. Balconies, decks and open stair landings shall not face the side property lines, except as needed to allow ingress and egress.
5.
Parking. Junior accessory dwelling units shall not be required to provide for any additional parking for the unit itself and is not required to replace any parking displaced by junior accessory dwelling unit construction, including full or partial conversion of an existing garage.
E.
Accessory Dwelling Units.
1.
Development Standard Waivers. Development standards regarding lot coverage, floor area ratio, impervious surface, and lot size shall be waived to allow a maximum eight hundred square foot detached or attached accessory dwelling unit with a maximum of sixteen feet in height, with minimum four-foot side and four-foot rear yard setbacks in compliance with all other applicable development standards. Permitted floor area and lot coverage requirements described by San Bruno Municipal Code Sections 12.96.060(D)(7) and 12.200.030 shall be waived to allow for an attached or detached ADU meeting the maximum size requirements described by subsection (E)(4).
2.
Setbacks. Attached and detached accessory dwelling units shall conform to the following setback standards:
a.
A minimum setback of four feet is required from the side and rear property lines. However, no setbacks shall be required under the following circumstances:
b.
There is no minimum requirement for setbacks between an accessory dwelling unit and the main residence; however, all proposals shall meet any applicable building and fire requirements.
3.
Passageway. No passageway shall be required in conjunction with the construction of an accessory dwelling unit.
4.
Size.
a.
The floor area of an attached or detached accessory dwelling unit on a lot with a proposed or existing single-family dwelling shall not exceed eight hundred fifty square feet for a studio or one bedroom and shall not exceed one thousand square feet for a unit that contains more than one bedroom for lots less than seven thousand five hundred square feet. For lots greater than or equal to seven thousand five hundred square feet, the floor area of an attached or detached accessory dwelling unit shall not exceed one thousand two hundred square feet for a unit that contains more than one bedroom.
5.
Architectural Compatibility. Compliance with the San Bruno Residential Design Architectural Compatibility. Compliance with Architectural Compatibility. Compliance with Guidelines is encouraged, but not required. A detached accessory dwelling unit with a single sloping or shed type roof shall be sited in a manner that causes the lowest eave line of the accessory dwelling unit to be located along the nearest side and/or rear property line and the highest eave line oriented toward the interior of the parcel. Notwithstanding the above, no design standards shall be required accessory dwelling units that meet the requirements of Government Code Section 66323(a) Sections 1 through 4.
6.
Balconies and Openings. Balconies, decks or open stair landings that face the rear or side property line nearest the accessory dwelling unit shall not be permitted, except as needed to allow ingress and egress. Windows within five feet of the property line shall utilize one of the following techniques to lessen the privacy impacts onto adjacent properties: obscured glazing, window placement above five feet, six inches (eye level), window orientation toward the existing on-site residence, or screening treatments.
7.
Height. The height of an accessory dwelling unit shall be measured in accordance with Section 12.80.246 and shall not exceed the following:
a.
A height of sixteen feet for a detached accessory dwelling unit on a lot with an existing or proposed single-family dwelling unit or existing or proposed single-story multifamily dwelling unit.
b.
A height of eighteen feet for a lot with existing or proposed multi-story multifamily dwelling units, or any single-family or multifamily lot that is within one-half of one mile walking distance of a major transit stop or a high-quality transit corridor, as those terms are defined in Section 21155 of the Public Resources Code.
c.
An additional two feet in height, beyond that which is allowed in subsection (E)(7)(a) and (b), shall be allowed to accommodate a roof pitch on a detached accessory dwelling unit that is aligned with the roof pitch of the primary dwelling unit.
d.
Allowed heights of accessory dwelling units attached to the primary dwelling shall adhere to the heights allowed for the primary dwelling. Accessory dwelling units located over legally established detached garages shall not exceed twenty-five feet in height. In no case shall an attached accessory dwelling unit exceed two stories. In the case of attached accessory dwelling units on single-family lots, no part of the accessory dwelling unit shall not be allowed above the second-story.
8.
Reserved.
9.
Off-Street Parking. Parking for an accessory dwelling unit shall be provided in compliance with the following standards:
b.
The additional parking space may be provided as uncovered tandem parking located in or adjacent to the required driveway for the primary residence or in the side yard as allowed per Chapter 12.100. Parking for the accessory dwelling unit may be located within setback areas unless the director finds that parking in setback areas is not feasible due to specific site or regional topographical conditions or fire and life safety conditions. Parking spaces shall not extend into a public sidewalk or right-of-way that would block pedestrian travel. Parking space dimensions must meet the requirements of the San Bruno Parking Design Standards.
c.
On-site parking is not required for an accessory dwelling unit in any of the following instances:
i.
The accessory dwelling unit is located within one-half mile of public transit.
ii.
The accessory dwelling unit is located within an architecturally and historically significant historic district.
iii.
The accessory dwelling unit is part of the existing or proposed primary residence or multifamily structure or an existing accessory structure.
iv.
When on-street parking permits are required but not offered to the occupant of the accessory dwelling unit.
v.
When there is a dedicated parking area for one or more car share vehicles located within one block of the accessory dwelling unit.
d.
Replacement parking is not required when a garage, carport, or covered parking structure is demolished for the construction of an accessory dwelling unit or converted to an accessory dwelling unit.
10.
New Address. The San Bruno building official shall assign a new address to the accessory dwelling unit.
(Ord. 1898 § 3, 2021; Ord. 1958, 1/28/2025)
§ 12.90.060 Occupancy
A.
An ADU or JADU shall not be rented for less than thirty days if permitted after January 1, 2020.
B.
A JADU shall require the recordation of a deed restriction that shall run with the land, be filed with the building department, and include both of the following:
1.
A prohibition on the sale of the JADU unit separate from the sale of the single-family residence, including a statement that the deed restriction may be enforced against future purchasers; and
§ 12.90.070 Delay of enforcement of building standards.
A.
Prior to January 1, 2030, the owner of an ADU that was built prior to adoption of the ordinance codified in this chapter, may submit a written request to the chief building official requesting that correction of any violation of building standards be delayed for five years. For purposes of this section, "building standards" refers to those standards enforced by local agencies under the authority of Section 17960 of the California Health and Safety Code.
B.
The chief building official will grant the application if the chief building official determines that enforcement of the building standard is not necessary to protect health and safety. In making this determination, the chief building official will consult with the Fire Marshal.
C.
No applications pursuant to this section shall be approved on or after January 1, 2030. However, any delay that was approved by the city before January 1, 2030, shall be valid for the full term of the delay that was approved at the time of the approval of the application.
D.
Until January 1, 2030, any notice to correct a violation of building standard that is issued to the owner of an ADU built prior to adoption of the ordinance codified in this chapter shall include a statement that the owner has a right to request a delay in enforcement of the building standard for an ADU pursuant to this section.
(Ord. 1898 § 3, 2021)
§ 12.90.080 Utilities and impact fees.
A.
For an accessory dwelling unit or junior accessory dwelling unit within the proposed space of a single-family dwelling or existing space of a single-family dwelling or accessory structure and which may include an expansion of not more than one hundred fifty square feet beyond the same physical dimensions as added for ingress/egress and that otherwise complies with Government Code Section 66323(a)(1), a new or separate utility connection directly between the accessory dwelling unit and the utility is not required. A related connection fee or capacity charge is also not required, unless the accessory dwelling unit was constructed with a new single-family dwelling, or upon separate conveyance of the accessory dwelling unit pursuant to Government Code Section 66342.
B.
For an accessory dwelling unit not within the proposed space of a single-family dwelling or existing space of a single-family dwelling or accessory structure, a new or separate utility connection directly between the accessory dwelling unit and the utility is required. Consistent with Government Code Section 66013, the connection will 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.
(Ord. 1898 § 3, 2021;Ord. 1958, 1/28/2025)