69.05 ACCESSORY DWELLING UNITS
69.05.1 Purpose and Findings. The provisions of this chapter are intended to set forth standards in accordance with State law for creation or conversion of at least one (1) accessory dwelling unit (ADU) per lot zoned to allow single-family or multifamily dwelling residential use. In addition, this section allows a Tiny House or Moveable Tiny House as defined in Sections 314-155 and 314-148 as an ADU when developed consistent with this section. An ADU does not exceed the allowable density for the lot on which it is located.
For purposes of this section, a junior accessory dwelling unit (JADU) is an attached unit that is no more than five hundred (500) square feet, contained entirely within a single-family structure, as defined in California Government Code Section 65852.22. JADUs are principally permitted in all areas where ADUs are principally permitted, and special rules apply as set forth in Section 314-69.05.3.8.
69.05.2 Accessory Dwelling Units Generally Permitted. Accessory dwelling units may be principally permitted in any zone that allows single-family or multifamily dwelling residential use and includes a proposed or existing dwelling, if the General Provisions in Sections 314-69.05.3 are met, and the ADU meets the Development Regulations and Standards of Section 314-69.05.4.
ADUs may be excluded or may require a Special Permit in certain designated areas as described in Section 314-69.05.6, based on adequacy of water and sewer services and the impact of accessory dwelling units on traffic flow and public safety. Outside the ADU Special Permit Area, an ADU that cannot meet all the criteria in Section 314-69.05.4 may still be permitted with a Special Permit under certain circumstances.
The County shall act on a complete building permit application for an accessory dwelling unit within sixty (60) days from the date the completed application is received if there is an existing single-family or multifamily dwelling on the lot.
69.05.3 Provisions that Apply to All ADUs. The following provisions apply to all ADUs:
69.05.3.1 One or More ADUs per Lot. One or more ADUs are permitted per lot developed or proposed to be developed with a single-family or multifamily dwelling, except for AE lots forty (40) acres or larger in size, where an ADU unrestricted in size may be allowed in addition to a main residence. Configurations with more than one (1) ADU are allowed in residential and mixed use zones, as described in Section 314-69.05.3.8.
69.05.3.2 Ownership. An ADU shall not be sold separately from the principal dwelling, except that Moveable Tiny Houses may be sold when removed from the lot.
69.05.3.3 Renting Permitted. The ADU may, but need not be, rented.
69.05.3.4 Short-Term Lodging Prohibited. The ADU shall not be rented for periods of thirty (30) days or less.
69.05.3.5 Building Type. The ADU may be within, attached to, or detached from, the existing or proposed principal residence and may be over a garage. An ADU may also be a Tiny House as defined in Section 314-155; a Moveable Tiny House as defined in Section 314-148; or a manufactured home as defined in Section 18007 of the Health and Safety Code.
69.05.3.5.1 Manufactured Homes as Accessory Dwelling Units. A manufactured home certified under the National Manufactured Housing Construction and Safety Standards Act of 1974 is permitted as an ADU with a building permit on parcels where single-family residences are allowed. It may or may not be placed on a permanent foundation, but must meet building and zoning regulations, skirting requirements, and foundation or setup configurations as described in Section 314-126.96.36.199.
69.05.3.5.2 Tiny Houses and Moveable Tiny Houses as ADUs. A Tiny House as defined in Section 314-155 that meets all applicable building and development standards in this Code is deemed a single-family dwelling, and is allowed as an ADU. A Moveable Tiny House as defined in Section 314-148 that meets all applicable building and development standards in this Code, and meets the criteria in Section 314-69.05.5, is deemed a single-family dwelling and is allowed as an ADU.
69.05.3.6 Sewer and Water Service. All new ADUs within Urban Service Areas shall connect to public wastewater systems if wastewater treatment is available. Where wastewater treatment is not available, a private sanitation and/or water supply system must meet County Health Department requirements. Outside Urban Service Areas, sanitation facilities, plumbing, and water supply for the ADU, including any septic or waterless toilet systems used, shall comply with all applicable County Health Department requirements for sewage disposal and water supply.
69.05.3.7 Existing Single-Family Residence. Where one (1) single-family dwelling unit exists on a lot, a larger home may be constructed as the principal dwelling unit, and the existing unit treated as the ADU, provided all other development regulations and standards can be met for both units.
69.05.3.8 ADU and Junior Accessory Dwelling Unit (JADU) Configurations Within Residential and Mixed Use Zones. For purposes of this section, a junior accessory dwelling unit (JADU) is an attached unit contained within the footprint of a primary dwelling, as defined in Government Code Section 65852.22. A building permit shall be ministerially approved for creation of any of the following, within a residential or mixed use zone:
69.05.3.8.1 ADU or JADU Within Existing Single-Family Structure. One (1) accessory dwelling unit per lot with a proposed or existing single-family dwelling if all of the following apply:
69.05.3.8.1.1The accessory dwelling unit or junior accessory dwelling unit is within the proposed space of a single-family dwelling, or within the existing space of a single-family dwelling or accessory structure, and may include an expansion of not more than one hundred fifty (150) square feet beyond the same physical dimensions as the existing accessory structure. An expansion beyond the physical dimensions of the existing accessory structure shall be limited to accommodating ingress and egress.
69.05.3.8.1.2The ADU or JADU has separate exterior access from the proposed or existing single-family dwelling.
69.05.3.8.1.3The side and rear setbacks are sufficient for fire and safety as established either by the local fire authority, or by Fire Safe regulations if the site is within a State Responsibility Area for fire response.
69.05.3.8.1.4The junior accessory dwelling unit complies with the requirements of Government Code Section 65852.22 including a maximum size of five hundred (500) square feet floor area.
69.05.3.8.2 New Detached ADU. One detached, newly constructed accessory dwelling unit with minimum four (4) foot side and rear yard setbacks is allowed on a lot with a proposed or existing single-family dwelling. In addition to the detached accessory dwelling unit, one (1) JADU is allowed on the lot, if the JADU is within a single-family or accessory structure as described in Section 314-69.05.3.8.1, and:
69.05.3.8.2.1The detached ADU contains no more than eight hundred (800) square feet of floor space, and its height is no more than sixteen (16) feet.
69.05.3.8.3 ADUs in Existing Multifamily Structures. Multiple accessory dwelling units 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. At least one (1) accessory dwelling unit is allowed within an existing multifamily dwelling, and up to twenty-five percent (25%) of the existing multifamily dwelling units may be allowed.
69.05.3.8.4 Detached ADUs with Existing Multifamily Structures. Not more than two (2) accessory dwelling units that are located on a lot that has an existing multifamily dwelling, but are detached from that multifamily dwelling, subject to a height limit of sixteen (16) feet and four (4) foot rear yard and side setbacks.
69.05.4 Development Regulations, Standards, and Applicable Codes. The following development regulations and standards shall apply to all ADUs:
69.05.4.1 Utilities. Utilities may be shared in common with or separate from the main dwelling unit, whichever method may afford compliance with the applicable requirements of the County Code, including the currently effective versions of the Uniform Building Codes and Uniform Plumbing Codes, except that:
69.05.4.1.1 Connection and Capacity Fees. An accessory dwelling unit shall not be considered to be a new residential use for the purposes of calculating connection fees or capacity charges for utilities, except for water and sewer services as set forth in Section 314-69.05.4.1.4, unless the accessory dwelling unit was constructed with a new single-family dwelling.
69.05.4.1.2 Impact Fees. A local agency, special district, or water corporation shall not impose any impact fee upon the development of an accessory dwelling unit less than seven hundred fifty (750) square feet. Any impact fees charged for an accessory dwelling unit of seven hundred fifty (750) square feet or more shall be charged proportionately in relation to the square footage of the primary dwelling unit. For purposes of this subsection, “impact fee” has the same meaning as the term “fee” as defined in subdivision (b) of Government Code Section 66000, except that it also includes fees specified in Section 66477. “Impact fee” does not include any connection fee or capacity charge charged by a local agency, special district, or water corporation.
69.05.4.1.3 No New Connections in Existing Structures. No new or separate utility connection shall be required between the ADU and the utility, and no related connection fee or capacity charge shall be imposed if the ADU is contained within the existing space of a single-family residence or accessory structure and meets conditions in Section 314-69.05.3.8.1 unless the accessory dwelling unit was constructed with a new single-family dwelling.
69.05.4.1.4 New Detached Units. For an accessory dwelling unit that is not contained within the existing space of a single-family residence or accessory structure or does not meet conditions in Section 314-69.05.3.8.1, a local agency, special district, or water corporation may require a new or separate utility connection directly between the accessory dwelling unit and the utility. Consistent with Government Code Section 66013, the connection may be subject to a connection fee or capacity charge that is proportionate to the burden of the proposed accessory dwelling unit upon the water or sewer system, based upon either size or the number of plumbing fixtures, its size in square feet or 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. This fee or charge shall not exceed the reasonable cost of providing this service.
69.05.4.1.5 Districts Under Moratoria or Compliance Orders. A service district, resort improvement district, or community service district that is under a moratorium on new connections, or under a compliance order for treatment issues, may not be compelled to provide water or sewer service for an accessory dwelling unit.
69.05.4.2 Building Site. The building site shall be shared in common with the proposed or existing primary residence. ADUs must meet local building code requirements that apply to detached dwellings, as appropriate. In areas zoned TPZ or AE, the curtilage area for residences, ADUs, driveways, utilities and associated residential accessory structures shall not exceed two acres per parcel and, where feasible, shall be located in the area of lowest agricultural productivity.
69.05.4.3 Total Floor Area. The total floor area of a detached ADU shall not exceed one thousand two hundred (1,200) square feet. If there is an existing primary residence, the total floor area of an attached accessory dwelling unit shall not exceed fifty percent (50%) of the area of the existing primary residence or one thousand two hundred (1,200) square feet. The minimum floor area shall be one hundred fifty (150) square feet. Floor area includes all enclosed habitable living space but excludes sheds, garages and storage areas.
69.05.4.3.1ADUs that exceed one thousand two hundred (1,200) square feet or attached ADUs that exceed fifty percent (50%) of the area of the existing primary residence may be permitted with a Special Permit.
69.05.4.4 Sprinklers. Accessory dwelling units are not required to provide fire sprinklers if they are not required for the primary residence.
69.05.4.5 Setbacks. No setback shall be required for an ADU or a portion of an ADU, converted from an existing living area or accessory structure, or a structure constructed in the same location and to the same dimensions as an existing structure. A setback of no more than four (4) feet from the side and rear lot lines shall be required for an ADU that is not converted from an existing structure or a new structure constructed in the same location and to the same dimensions as an existing structure.
69.05.4.6 Parking. Each ADU requires one (1) parking space. These spaces may be provided in tandem on a driveway. Off street parking shall be permitted in setback areas or through tandem parking, unless specific findings are made that parking in setback areas or tandem parking is not feasible based upon specific site or regional topographical or fire and life safety conditions.
69.05.4.6.1 Exceptions to Parking Standards. Parking standards for an ADU shall not apply if the ADU is (1) located within one-half mile walking distance of public transit; (2) located within an architecturally and historically significant district; (3) part of the proposed or existing primary residence or an existing accessory structure; or (4) when on-street parking permits are required but not offered to the occupant of the ADU; or (5) when there is a car share vehicle located within one (1) block of the accessory dwelling unit. In mapped Housing Opportunity Zones, for ADUs less than one thousand (1,000) square feet in size, no parking shall be required.
69.05.4.7 No Frontage Improvements. No frontage improvements shall be required for ADUs.
69.05.4.8 Height Limits. Height limits for accessory dwelling units and junior accessory dwelling units must allow at least sixteen (16) feet in height, in spite of the general height limit of fifteen (15) feet set by Section 314-102.1.
69.05.5 Moveable Tiny House as an ADU. In addition to the other provisions of this section, Movable Tiny Houses as defined in Section 314-148 used as ADUs shall comply with all of the following provisions:
69.05.5.1 Skirting. The undercarriage (wheels, axles, tongue and hitch) must be hidden from view.
69.05.5.2 Foundation or Pad.
69.05.5.2.1 Foundation. If the wheels are removed so the unit may sit on a foundation, the foundation requirements for a Movable Tiny House shall follow the State approved requirements for foundation systems for manufactured housing, or follow an alternative design certified by a licensed engineer.
69.05.5.2.2 Paved or Alternate Pad. If the wheels are not removed, the parking area shall include bumper guards, curbs, or other installations adequate to prevent movement of the unit. The wheels and leveling or support jacks must sit on a paving surface compliant with either of the following.
69.05.5.2.2.1 Paving. A parking area for a moveable tiny house on wheels shall be paved with hard, durable asphaltic paving that has been mixed at a plant and is at least two (2) inches thick after compaction, with Portland cement paving at least three (3) inches thick, or an alternative as described below.
69.05.5.2.2.2 Alternative Paving Materials. An alternative paving material is one (1) of the following: porous asphalt, porous concrete, permeable interlocking concrete pavers, permeable pavers, decomposed granite, crushed rock, gravel, and restrained systems (a plastic or concrete grid system confined on all sides to restrict lateral movement, and filled with gravel or grass in the voids). Alternative paving materials are permitted subject to all the following requirements:
69.05.5.2.2.2.1Permeable interlocking concrete pavers and permeable pavers shall have a minimum thickness of eighty (80) mm (3.14 inches).
69.05.5.2.2.2.2Products and underlying drainage material shall be installed to meet manufacturers’ specifications. Sub-grade soils shall be compacted as required to meet the product installation specifications.
69.05.5.3 Mechanical Equipment. Mechanical equipment shall be incorporated into the structure and not located on the roof.
69.05.5.4 Sprinklers. Moveable Tiny Houses are not required to have sprinklers, but shall follow the ANSI 119.5 standards relating to health, fire and life-safety.
69.05.5.5 Applicable Codes. Moveable Tiny Houses shall meet either the provisions of ANSI 119.5 or NFPA 1192 standards, or the provisions of the California Building Code, including 2019 California Residential Code Appendix Q, Tiny Houses, or other adopted alternatives, or both.
69.05.5.6 Design Standards. Moveable Tiny Houses must comply with all requirements for Detached ADUs and shall have the following design elements:
69.05.5.6.1Materials used as exterior wall covering shall be natural or man-made, nonreflective materials; and no more than ten percent (10%) of the exterior may be reflective in nature;
69.05.5.6.2Windows shall be at least double pane glass and labelled for building use, and shall include exterior trim;
69.05.5.6.3Roofs shall have a minimum of a 1:12 pitch for greater than fifty percent (50%) of the roof area;
69.05.5.6.4The unit shall be plumbed to allow connection to an approved means of sewage disposal, septic system, or waterless toilet. Portable or enclosed waste storage tanks are not allowed for sewage disposal.
69.05.5.6.5A Moveable Tiny House need not be connected to a source of electrical power, but if it is, the installation shall be in accordance with the California Electrical Code, Part 3, Title 24, California Code of Regulations.
69.05.6 ADU Special Permit Area. Lots located in the ADU Special Permit Area, as mapped, are presumed to have certain water and sewer service limitations, adverse impacts on traffic flow, and/or public safety conditions that may preclude construction of an ADU, so that an ADU in that area may require a Special Permit. These conditions are:
69.05.6.1Areas outside a Fire Protection District;
69.05.6.2Airport incompatibility. A Special Permit may not be issued if the ADU exceeds the density limit in an airport zone;
69.05.6.3Areas of active or historic landslides, or areas of potential liquefaction;
69.05.6.4Flood and tsunami hazards; and
69.05.6.5Proximity to toxic cleanup sites as designated by California Department of Toxic Substances.
On a parcel within a mapped ADU Special Permit Area due to one (1) or more of the conditions above, an ADU may be allowed with a Special Permit if substantial evidence shows that the health and safety conditions for which it was included do not apply to that site, or can be successfully reduced or mitigated to less than significant levels.
69.05.7 Delayed Enforcement of Building Code Violations. Any owner of an existing ADU built before the effective date of the ordinance codified in this section, who receives notice of a building code violation, may request a delay in enforcement for five (5) years. The Chief Building Official must grant the delay if the correction is not required to protect health and safety.
69.05.8 Accessory Dwelling Units Allowed With Alternative Owner Builder Residence. An accessory dwelling unit may be permitted under the Alternative Owner Builder Code, Chapter 1.5 of Division 3 of Title III, in rural areas outside a community service district boundary; provided, that all the requirements of this Code and of the Alternative Owner Builder Code are met, including that:
69.05.8.1An inspection of the dwelling has been made by the appropriate County official(s); and
69.05.8.2The Official(s) determine(s) that the requirements of the applicable County Codes, including modifications, have been met or substantially met to the extent that no abnormal risk to health or safety will result from occupancy of the dwelling; and
69.05.8.3All other conditions applicable to accessory dwelling units have been met.
69.1 ACCESSORY STRUCTURES
69.1.1 Permitted Agricultural Accessory Structures. The following accessory structures shall be permitted in the (AE) Agricultural Exclusive, (AG) Agriculture General, and (TPZ) Timber Production zones: (See also, Permitted Agricultural Accessory Uses, Section 314-43.1, for principal permitted uses in AE, AG and TPZ zones.) (Former Section INL#316-2.1; Added by Ord. 2189, Sec. 1, 2/9/99)
188.8.131.52Windmills, not including windmills that produce energy for export off of the ranch or farm; (Former Section INL#316-2.1(1); Added by Ord. 2189, Sec. 1, 2/9/99)
184.108.40.206Greenhouses which do not result in lot coverage exceeding 5 acres on lots 20 acres or larger in size, or exceeding 25% of the lot coverage for lots less than 20 acres in size, either individually or collectively, with or without a perimeter foundation, and without an improved floor or footpath which will preclude the agricultural use of the underlying soil. Greenhouses with an improved floor or footpath which will preclude the agricultural use of the underlying soil shall not be located on prime agricultural soils, but may be located on non-prime agricultural soils with a Special Permit. Concrete, asphalt, and similarly constructed footpaths are permitted within a greenhouse located on non-prime agricultural soils, and may be permitted on prime agricultural soils with a Special Permit. (Former Section INL#316-2.1(2); Added by Ord. 2189, Sec. 1, 2/9/99)
220.127.116.11Silos; (Former Section INL#316-2.1(3); Added by Ord. 2189, Sec. 1, 2/9/99)
18.104.22.168Tank Houses; (Former Section INL#316-2.1(4); Added by Ord. 2189, Sec. 1, 2/9/99)
22.214.171.124Barns and outbuildings; (Former Section INL#316-2.1(5); Added by Ord. 2189, Sec. 1, 2/9/99)
126.96.36.199Coops; (Former Section INL#316-2.1(6); Added by Ord. 2189, Sec. 1, 2/9/99)
188.8.131.52Drainage facilities and structures. (Note: In the Coastal Zone these facilities and structures are subject to the following regulations, as applicable: Coastal Wetlands, Streams and Riparian Corridors Protection, Transitional Agricultural Lands, and Chapter 2: Procedures); (Former Section INL#316-2.1(7); Added by Ord. 2189, Sec. 1, 2/9/99)
184.108.40.206 Roadside Stands/Sales of Agricultural Products. Operation of a single roadside stand for the display and sales of only those products produced on the premises, or on other property owned or leased by the vendor, as permitted by these regulations, provided that the stand does not exceed an area of 200 square feet, and is located not nearer than fifteen (15) feet from any street or highway right-of-way.
220.127.116.11Public Stables for 6 horses or less. Public stables for 7 or more horses may be permitted with a Special Permit. (Former Section INL#316-2.1(9); Added by Ord. 2189, Sec. 1, 2/9/99)
18.104.22.168 Other Necessary and Customary Structures.
22.214.171.124.1Accessory structures in addition to those identified in this Chapter, which are necessary and customarily associated with, and are appropriate, incidental and subordinate to agricultural activity as determined by the Director. (Former Section INL#316-2.1(10); Added by Ord. 2189, Sec. 1, 2/9/99)
126.96.36.199.2Buildings or structures, which result in lot coverage exceeding 5 acres on lots 20 acres or larger, or exceed 25% lot coverage on lots less than 20 acres, either individually or collectively, shall not be permitted as agricultural accessory structures and shall only be permitted with a Special Permit. (Former Section INL#316-2.1(10); Added by Ord. 2189, Sec. 1, 2/9/99)
Airports, heliports and landing strips for aircraft shall be permitted with a Use Permit in any zone. However, a Use Permit is not required for principal permitted uses in AV zones. (Former Section INL#316-3; Ord. 519, Sec. 603, 5/11/65)