a.    Definitions.

1)    "Accessory structure" is an attached or detached (to the main building) building, carport, gazebo, shed, playhouse, or other similar aboveground structure, the use and size of which is subordinate and incidental to that of a main building on the same lot;

2)    "Fully enclosed" shall mean an accessory structure that is closed on all sides, such as an outdoor room with walls or windows surrounding, backyard shed, greenhouse, or detached garage;

3)    "Partially enclosed" shall mean an accessory structure that is closed on at least two but no more than three sides, such as an outdoor room (e.g., California room), and covered deck, patio, or porch;

4)    "Unenclosed" shall mean an accessory structure that is open on at least three sides, such as a covered deck, covered patio, or carport; and

5)    "Shipping container" (also referred to as intermodal freight transport, sea container, or cargo container) is typically a twenty (20) to forty (40) foot long durable closed steel container capable of handling large capacity and weight loads over land and sea.

b.    Maximum Size and Height.

1)    Maximum Size. The maximum size of an accessory structure or combination of accessory structures on any single lot shall be whichever results in a greater allowance of accessory structure square footage between the following two options: (1) as measured in conjunction with all structures on the lot so that the total lot coverage shall not exceed forty percent (40%); or (2) five hundred (500) square feet. Square footage of structures shall be measured as follows:

a)    For enclosed structures, such as the main house, detached garages, detached guest rooms/pool houses, enclosed patios, etc., floor area (interior walls to interior walls) shall be used to measure square footage; and

b)    For unenclosed structures, such as gazebos, attached and detached carports, patio covers, trellises, etc., roof area coverage (as measured perpendicular to ground) shall be used to measure square footage.

2)    Maximum Height. The maximum height for any single accessory structure as measured to the peak of the roof or highest portion of the structure, whichever is higher, shall be as follows:

a)    Fifteen (15) feet in height when the accessory structure or portion thereof is located within any of the required yards for the applicable zoning district; and

b)    Accessory structures completely located outside of all required yards, subject to the applicable zoning regulations, may exceed fifteen (15) feet in height. All accessory structures exceeding fifteen (15) feet in height shall use materials, design, and colors that complement and/or match the main structure, subject to the review and approval of the Planning Division.

c.    Minimum Setbacks.

1)    All Residential Lots.

a)    Accessory structures shall be located outside of the required front yard (front yard setback) and shall not have any portion closer than the main house to the front property line, except: (1) unenclosed, nonsolid roof gazebos, pergolas or similar structures may be located in front of the house, but not within the required front yard setback; (2) decorative landscape trellises and arbors covering no more than thirty-two (32) square feet and no more than eight feet tall may be located within the required front yard, but not within the public right-of-way; and (3) accessory structures that match or complement the design, materials, and colors of the main house on large lots (forty thousand (40,000) square feet or larger) where the accessory structure is located a minimum of fifty (50) feet behind the front property line, subject to the review and approval of the Planning Division;

b)    Detached accessory structures that are exempt from a building permit and are no higher than the height of the adjacent fence to which they are to be placed may be located within the required side or rear yard of any lot, up to the property line, only if the accessory structure maintains a minimum clearance of five feet to any other structure, excluding the fence. No accessory structure may be attached to a shared fence;

c)    All detached "fully enclosed," detached "partially enclosed," and detached or attached "unenclosed" accessory structures that are one thousand five hundred (1,500) square feet or less shall maintain a minimum setback of three feet to the side and rear property lines. No portion of an accessory structure, its roof, or any other material that is a part of the accessory structure (i.e., overhang, gutter, support beam, etc.) shall project into the minimum setback;

d)    Single structures that are greater than one thousand five hundred (1,500) square feet shall maintain the generally applicable setback standards for the relative zoning district; and

e)    For all attached "fully enclosed" and attached "partially enclosed" accessory structures, refer to Section 9.1.1122(g).

2)    Nonresidential Districts. The minimum setbacks for accessory structures in nonresidential districts shall be the generally applicable setback standards for each district.

d.    Maximum Coverage in Required Rear and Side Yards.

1)    Consistent with Section 9.1.404(f)(5), accessory structures shall occupy no more than fifty percent (50%) of a required rear yard. This shall also apply to the maximum coverage of a required side yard as measured from the front setback line to the rear property line. For structures located within both a required rear yard and required side yard, the area of coverage shall apply to the maximum allowable coverage for each required yard separately.

e.    Design Standards.

1)    Accessory structures shall be consistent with the City of Oakley Residential Design Guidelines, which include having matching materials and architectural style to that of the primary unit.

2)    Accessory structures may consist of pre-built or pre-fabricated sheds, carports, gazebos, etc., that do not match the material of the primary unit so long as the accessory structure’s original design, intent, purpose, and placement is as a residential backyard structure.

3)    Shipping containers are not permitted as residential accessory structures unless the following criteria can be met, subject to the review and approval of the Community Development Director:

a)    The shipping container is redesigned and repurposed to appear and function as a residential accessory structure through the additional of a pitched roof that matches the color of the primary unit’s roof, and the addition of texture coating or exterior veneer to disguise the industrial appearance of such structures and that matches the color of the primary unit;

b)    The shipping container is structurally modified to include at least one residential main door that can be unlocked and opened from inside the container; and

c)    Subject to review and approval of the Community Development Director, exceptions may be made for the standard in subsection (e)(3)(a) of this section if the shipping container is screened from public and private view by a solid fence as seen from adjacent ground level.

f.    Variance Requests.

1)    Any request for an exception to this article shall be subject to Section 9.1.1602, Variance and Conditional Use Permits.

(Sec. 1, Ordinance No. 21-19, adopted December 10, 2019; Sec. 1, Ordinance No. 05-18, adopted April 10, 2018; Sec. 1, Ordinance No. 07-17, adopted May 23, 2017; Sec. 5, Ordinance No. 18-16, adopted August 9, 2016; Ordinance No. 16-13, adopted December 10, 2013; Sec. 2, Ordinance No. 10-13, adopted August 13, 2013; Sec. 1, Ordinance No. 08-10, adopted May 25, 2010; Sec. 2(C), Ordinance No. 05-10, adopted March 9, 2010)