A second permanent dwelling may be allowed in compliance with this section in addition to the first dwelling on a site allowed by Section 22.10.130 (Residential Density), provided the site and the existing primary dwelling comply with all other applicable provisions of this title. (A caretaker residence is subject to Section 22.30.430, farm support quarters, are subject to Section 22.30.480.)
A. Authority. Secondary dwellings are authorized in compliance with the authority established by Government Code Sections 65852.2 et seq.
B. Limitations on Use.
1. Accessory Unit Only. A secondary dwelling shall be accessory to a primary dwelling and shall not be established on any site containing a guesthouse (Section 22.30.410) or more than one dwelling unit, except where a guesthouse is proposed to be converted to a secondary unit in compliance with this section.
2. Occupancy of Primary and Secondary Units Restricted. No secondary dwelling shall be approved in compliance with this section unless an owner of the site agrees to occupy one unit on the site as his or her primary residence. Prior to final building inspection, the applicant for a second unit shall record a notice against the property notifying any subsequent purchaser that failure to meet this requirement will subject the second unit to abatement by the county in compliance with Chapter 22.10.
C. Limitations on Location.
1. Excluded Areas. A secondary dwelling shall not be allowed within the following areas, where secondary units are deemed incompatible with existing development, or where the density increase from secondary units would create adverse cumulative effects on essential community services and natural features. These services and features include but are not limited to water supplies, storm drainage facilities, roadway traffic capacities, and soils with limited suitability for septic system sewage disposal, or that are subject to erosion.
a. Atascadero. The areas south of the Atascadero urban reserve line within the Residential Suburban land use category, as defined by the Land Use Element, Salinas River area plan, except for parcels with direct driveway access to El Camino Real.
b. Nacimiento Area. The areas identified by the Land Use Element, Nacimiento area plan as being within the South Shore Area or the villages of Heritage Ranch or Oak Shores.
c. Specific Subdivisions. Secondary dwellings are not allowed within Tracts 7, 17, 19, and 502.
d. Regional Water Quality Control Board (RWQCB) exclusion. All areas of the county where the RWQCB has issued a notice of resource constraints through moratoria or other means.
D. Application Content. In addition to the information required by Section 22.62.030, information submitted with the zoning clearance application shall also indicate whether or not there are conditions, covenants or restrictions applicable to the site that would prohibit a secondary dwelling. This information will not be grounds for county denial of a permit.
E. Minimum Site Area. A secondary dwelling may be allowed only on sites with the following minimum areas:
1. Six thousand square feet for sites served by community water and sewer facilities;
2. One acre (net) where on-site water supply and sewage disposal systems are proposed on an existing parcel, provided that all applicable requirements for separation between the existing septic system, new septic system for the secondary dwelling and any on-site and off-site water wells are satisfied, as well as all other applicable provisions of Title 19 of this Code for septic system design and performance; or
3. One acre (gross) where community water and on-site sewage disposal are proposed on an existing parcel, provided that all applicable provisions of Title 19 of this Code for septic system design and performance are satisfied.
Except that where a larger minimum site area requirement is established by planning area standards (Article 9), the larger area shall be required.
F. Design Standards.
1. The following apply to all land use categories where secondary dwellings are allowed.

Notes:

(1) Includes attics greater than six feet in height, unconditioned storage space and lofts.

(2) If the road that provides access to the property is maintained by the county, state or special district; the surfacing requirement does not apply. If the road is not maintained by the county, state or special district, the surfacing requirement applies and the road must be maintained through an agreement with property owners fronting the road or through an established homeowners association.

(3) Chip seal must be placed over a Class II, or better, base material as defined by California Department of Transportation standards along the property frontage and back to nearest maintained road.

2. Driveways. The driveways serving the primary and secondary dwelling shall be combined where possible. An adjustment may be granted in compliance with Section 22.70.030 if combining driveways is prohibited by a physical site constraint, would result in grading on slopes over fifteen percent, or would require the removal of oak trees or other native trees.
3. Within Urban and Village Reserve Lines.
a. The secondary dwelling shall employ a design style compatible with the primary dwelling.
b. When a secondary dwelling is attached to the primary dwelling, the entrances shall be designed to maintain the character of a single dwelling and to avoid the attached secondary dwelling changing the appearance of the primary dwelling to resemble a duplex. The entrance to an attached secondary dwelling shall not be located on the same building face as the entrance to the primary dwelling unless the entrance to both the primary and secondary dwellings is shared.
c. No more than fifty percent of the site shall be covered by structures.
4. Exceptions to Design Standards. The review authority may approve alternatives to the design standards of subsection F in compliance with Section 22.62.050, but shall not approve alternatives to any other provision of this section. The maximum size of unit as set forth in subsection (F)(1), and the maximum size of the garage workshop as set by subsection (F)(6), cannot be modified except by a variance (Section 22.62.070). The maximum distance from the primary unit may be adjusted in compliance with Section 22.70.030 where the secondary dwelling is proposed within an existing structure legally constructed prior to January 1, 2006 and there will be no physical change to the site (no additional footprint or garage space added to serve the secondary unit). Otherwise, the maximum distance from the primary unit may be modified only where the review authority first finds the following:
a. Locating the secondary dwelling within the distance as set forth in subsection (F)(1) would necessitate the removal of, or impact to, any of the following:
(1) Exiting improvements, such as swimming pools, wastewater disposal fields, drainage facilities, or water storage tanks;
(2) Sensitive or significant vegetation such as native trees or shrubs, riparian vegetation, vineyards, orchards, or visually prominent trees;
(3) Significant topographic features (steep slopes, ridgelines, bluffs) water courses, wetlands, lakes or ponds, or rocky outcrops;
(4) Archaeological resources.
5. Parking. A secondary dwelling shall be provided one off-street parking space per bedroom to a maximum of two spaces, in addition to those required for the primary residence by Chapter 22.18 (Required Parking Spaces—Residential Uses). The parking space shall be located, designed and constructed in compliance with Chapter 22.18, except that for lots of seven thousand five hundred square feet or less, the parking may be located within the front setback and tandem with the parking required for the primary dwelling.
6. Garage/Workshop. The garage/workshop for a secondary dwelling is limited to a maximum of fifty percent of the size of the secondary dwelling. Where the secondary dwelling is constructed on the second floor of the primary dwelling’s detached garage, no additional attached or detached garage/workshop shall be permitted.
G. Parking. A secondary dwelling shall be provided one off-street parking space in addition to those required for the primary residence by Chapter 22.18 (Required Parking Spaces—Residential Uses). The parking space shall be located, designed and constructed in compliance with Chapter 22.18. (Ord. 3097 §§ 10, 11, 2006; Ord. 2982 § 1 (part), 2002)