§ 16.52.150. Accessory dwelling units.

A.

Purpose and Intent. The purpose of these standards is to ensure that accessory dwelling units located in residential districts do not adversely impact either adjacent residential parcels or the surrounding neighborhood, and are developed in a manner which protects the integrity of the residential district, while providing for needed housing opportunities. There are environmental and service constraints the city faces, which limit the addition of accessory dwelling units. In particular, such dwellings may not be appropriate on hillside lots because of environmental constraints. The addition of an accessory dwelling is limited by urban service capacity, public safety standards, traffic conditions, fire hazards, privacy impacts and compatibility with neighboring uses and structures. This chapter addresses these limitations.

B.

Applicability.

1.

Accessory dwelling units may be permitted in any residential district, subject to the standards set forth in this section.

2.

Accessory dwelling units may be attached to or detached from the main dwelling, but are not allowed on the second floor above the primary residence or garage unless approved through the minor use permit - viewshed review process. If the accessory dwelling unit is attached to the main dwelling, each shall be served by separate outside entrances. The interior wall(s) of an attached dwelling which separate it from the main unit shall be fire rated according to the most recent uniform building code.

a.

An "attached accessory dwelling unit" shall mean a dwelling that is either combined within the living area or attached to the primary residence.

b.

A "detached accessory dwelling unit" shall mean a dwelling that is not combined within or attached to the primary residence.

c.

For the purposes of this chapter, "a dwelling" shall not include a garage or any accessory structure.

d.

"Primary residence" shall mean an existing detached residential structure that conforms with all applicable zoning regulations.

3.

An accessory dwelling unit may be constructed simultaneously with or after construction of the principal residence. In addition, an existing principal residence may be considered the accessory dwelling unit, and a new residence may be constructed which would then be considered the primary residence, provided the standards set forth in this section are met.

C.

Property Development Standards. The accessory dwelling unit shall comply with all zoning regulations and property development standards of the district in which it is located, existing building, health, safety and fire codes, and architectural review criteria, including, but not limited to, setbacks, height limits, floor area ratio, and maximum lot coverage. In addition, the following standards shall apply:

1.

Minimum Lot Size. The minimum lot size for a parcel to be eligible for an accessory dwelling unit shall be six thousand seven hundred fifty (6,750) square feet, excluding all rights-of-way and private access easements.

2.

Building Separation. A detached accessory dwelling unit shall be located a minimum distance equal to that identified for the applicable zoning district in Table 16.32.050-A.

3.

Yard Setbacks. The accessory dwelling unit shall have the same minimum yard setback requirements as the base zone of the primary residence on the parcel as outlined in Table 16.32.050-A and Table 16.32.050-B. Setbacks outlined in Appendix C.W.D.219 as referenced in Table 16.32.050-B and Table 16.32.050-A shall not be applicable to second residential dwellings. Accessory dwelling units constructed above a garage shall have the setback requirements of five feet in the side and rear yard, regardless of underlying minimum setback requirements.

4.

Architectural Compatibility. The accessory dwelling unit shall be architecturally compatible with the primary residence and the surrounding neighborhood, and shall incorporate the same colors and materials as the primary residence.

5.

Maximum Size. Table 16.52.150-A defines the maximum square footage allowed for an accessory dwelling unit in each residential zoning district. In no case shall the square footage of an accessory dwelling unit exceed fifty (50) percent of the square footage of the primary residence.

Table 16.52.150-A

Zoning Designation	Maximum Size of Accessory Dwelling Unit
Village Residential (VR)	850 square feet
Single-Family (SF)	850 square feet
Residential Suburban (RS)	1,200 sq. ft. for lots ≥ 12,000; 850 s.f. for lots < 12,000 s.f.
Residential Rural (RR)	1,200 square feet
Residential Hillside (RH)	1,200 square feet
Residential Estate (RE)	1,200 square feet
Condominium/Townhouse (MF)	1,200 square feet
Apartments (MFA)	1,200 square feet
Multifamily Very High Density (MFVH)	1,200 square feet
Mobile Home Park (MHP)	Not permitted (NP)

 

6.

Maximum Slope. The building site upon which the accessory dwelling unit will be constructed shall not have an average slope in excess of twenty (20) percent. A topographic map and slope analysis, as recommended by the community development director, shall be stamped and signed by either a registered civil engineer, registered architect, or registered landscape architect. Average slope is defined as follows:

S =	I x L	× 100
	A × 43,560

 

Where

S = average natural slope, in percent.

I = interval, in feet, of the contour lines.

L = the sum, in feet, of the length of the contour lines, at selected contour interval "I".

A = the total area, in acres, of the site.

7.

Parking. A minimum of one, off-street parking space shall be provided for each bedroom in the accessory dwelling unit, up to a maximum requirement of two, off-street parking spaces, in addition to the off-street parking spaces required for the main dwelling. Such parking spaces shall be located in close proximity to the accessory dwelling unit so as to provide convenient access for the occupant. These spaces may be provided as tandem parking, including on an existing driveway or in setback areas, excluding the non-driveway front yard setback.

a.

Additional parking shall not be required in the following cases:

i.

If the accessory dwelling unit is located within one-half mile by travelled distance of an existing transit stop;

ii.

The accessory dwelling unit is located in the D-2.4 Historic Character Overlay District;

iii.

The accessory dwelling unit is located in a neighborhood where on-street parking permits are required but not offered to the occupant of the accessory dwelling unit;

iv.

A car share vehicle is located within one block of the accessory dwelling unit.

v.

The accessory dwelling unit is part of the existing primary residence or an existing accessory structure.

8.

Replacement Parking. When a garage, carport, or covered parking structure is demolished or converted in conjunction with the construction of an accessory dwelling unit, replacement parking 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. This requirement shall not apply to projects described in Arroyo Grande Municipal Code Section 16.52.150.C.7.a.

9.

Driveway Access. Accessory dwelling units shall be served by the same driveway access to the street as the primary residence. Properties located on a corner of two public streets are allowed a separate access from the primary residence, provided that access for the accessory dwelling unit is from a different public street than the primary residence.

10.

Utility Meters. For any lot zoned for multiple family or single-family uses, the accessory dwelling unit may, but is not required to, have an electric, gas, or water meter, or sewer lateral, separate from the primary residence on the property. Applicable utility and development impact fees for the accessory dwelling unit will be assessed at the time a building permit is issued, based on building area and fixtures added.

11.

Conditional Use Permit or Minor Use Permit. Any proposed deviation from these standards shall be processed through a conditional use permit or minor use permit application as determined by the community development director.

12.

Other Conditions.

a.

Accessory dwelling units shall be served by city water. Accessory dwelling units shall be prohibited on lots containing a guesthouse, converted garage, mobile home, or more than one existing single-family dwelling.

b.

Accessory dwelling units shall comply with such other conditions or standards which, in the judgment of the city, are necessary or appropriate to mitigate possible adverse impacts on the neighborhood.

D.

Notwithstanding anything herein to the contrary, the city shall ministerially approve an application for a building permit to create within a single-family residential zone one accessory dwelling unit per single-family lot if the unit is contained within the existing space of a single-family residence or accessory structure, has independent exterior access from the existing residence, and the side and rear setbacks are sufficient for fire safety.

E.

State Law Applicable. The provisions of this section shall be subordinate to and superseded by the controlling provisions of any applicable state law or laws.

(Ord. 584 § 3, Exh. B (part), 2007; Ord. 573 Exh. A (part), 2005; Ord. 541 § 1, 2003: Ord. 519 § 1, 2000: prior code § 9-11.140)

(Ord. No. 645, § 5, 8-28-2012; Ord. No. 688, § 2, 10-24-2017)

Editor's note

Ord. No. 688, § 2, adopted Oct. 24, 2017, changed the title of § 16.52.150 from "Second residential dwellings" to read as herein set out.