18.80.020 Accessory buildings or structures

18.80.020 Accessory buildings or structures.

1. The provisions of this section apply to roofed structures, including but not limited to garages, carports, sheds, workshops, arbors, gazebos, pergolas, and covered patios, that are detached from and accessory to the main building on the site. These provisions also apply to open, unroofed structures, such as decks and trellises, that are over six feet in height and that are detached from and accessory to the main building on the site.

2. When an accessory building or structure is attached to the main building, it shall be made structurally a part of and have a common wall or roof with the main building and shall comply in all respects with the requirements of this code applicable to the main building and all other applicable codes. Allowed building projections into setbacks are stated in MCC 18.80.040, Building projections into yards.

3. Where guest quarters are located over a detached garage, the entire structure shall be considered a main building, subject to the zoning district standards for main buildings. No portion of this building shall be closer to any lot line than is permitted for any other main building, except on an alley where the detached garage may be within the setback.

B. Relation to Existing Structures. A detached accessory building may only be constructed on a lot on which there is a permitted main building to which the accessory building is related. An accessory building on an adjacent lot under the same ownership is not allowed; the two lots must be merged. However, an accessory building may be constructed prior to a permitted main building and used for not more than one year in connection with the construction of the main building; provided, that a permit is obtained for the entire project, including the accessory building, prior to the start of any construction.

C. Location. Accessory structures shall be located behind the front line of the primary structure, unless otherwise specified in this code.

1. Corner Lot. On a corner lot, no detached accessory building shall be located so as to project beyond the required front yard or the existing front line of the primary structure on any street frontage for lots less than one acre.

2. Through Lot. On a through lot having frontage on two more or less parallel streets, no detached accessory building shall be located within one-fourth of the lot area of either street-facing property line.

D. Detached Garage Exception. In rural districts, and on large lots in residential districts (12,000 square feet or more), garages may be allowed on the front half of a lot if permitted by the development standards for the applicable zoning district.

E. Development Standards. Detached accessory buildings or structures shall comply with the development standards provided in Table 18.80.020B and observe the regulations set forth in MCC 18.80.040, Building projections into yards. The following building standards work in conjunction with base standards. If conflicting with development standards outlined in Division 2 or Division 3 of this title, those standards override these regulations.

Table 18.80.020.B Development Standards – Detached Accessory Buildings
	Specific Criteria
Building Standards	120 s/f or less	Exceeds 120 s/f	Guest Quarters
Height (ft)	15	15	15 (1)
Setbacks, min. (ft)	3 (2), (3)	5	Same as main building per zoning district’s development standards (4)
Rear Yard Area	30% maximum of rear setback area – See Figure 18.80.020.E.2
	This regulation is not to supersede the overall lot coverage for all roofed buildings/structures on the lot (see base zone district, lot coverage)
Separation from Main Building	Six feet measured from roof eave to roof eave
(1) Guest quarters above garages: 25 feet maximum height allowed with pitched roof.
(2) Structures shall observe five feet of setback that: (a) exceed 25 feet in length or width, or (b) measure in excess of one-third of the width of the rear property line. See Figure 18.80.040.
(3) Location relative to adjacent lot: if laterally forward of the adjacent lot’s front half point, observe five feet of setback.
(4) Except when above a garage facing an alley, this condition shall observe the criteria of structure square footage.

F. Rear Yard Area. Detached accessory structures shall not occupy more than 30 percent of the required rear yard setback.

1. A detached accessory structure that has not been approved as a guest quarter may contain bathroom facilities upon review and approval by the zoning administrator and the building official. The applicant shall obtain all necessary building permits for work to be performed. The applicant shall sign a statement, at the time of submittal for a building permit, which will prohibit the use of the accessory structure as a second dwelling unit. The signed statement shall be in the form of a restrictive covenant and shall be recorded.

2. A detached accessory structure shall not have plumbing for separate housekeeping facilities, such as a kitchen or laundry facilities, unless it has been approved as a guest quarter, meeting the standards in MCC 18.120.010.

H. Permits. Accessory structures greater than 120 square feet for residential structures and 200 square feet for commercial structures shall require zoning administrator approval.

I. Factory-Built Modular Buildings. Factory-built modular buildings designed, manufactured, and attached to permanent foundations are permitted in all districts; provided, that such buildings are installed in conformance with all applicable provisions of this code.

J. Modular storage containers, such as corrugated metal shipping containers, are permitted in all districts as accessory structures under the following conditions:

1. The containers are not visible from the right-of-way (meaning from the public road);

2. The containers do not disrupt the flow of traffic within the parking lot; and

3. The containers are modified so they do not look like containers (i.e., painted to match the building, siding installed, etc.). [Res. 21-09; Ord. 21-05 § 2; Res. 14-36 § 401.02; Ord. 14-12 § 1.]