Accessory Structure Requirements

Accessory structures are detached buildings or structures such as private garages, sheds, carports, decks, patio covers, pools and similar structures. Such structures are constructed to serve an existing residence and are subject to Riverton City Zoning Ordinance including the Building Code.

Garage & Sheds Helps Diagram

Permits
A building permit is required for accessory structures, except for one story detached accessory structures used as sheds, playhouses and similar small buildings that are 200 square feet or less in floor area and not over 16 feet in height. A building permit is required for any plumbing, electrical or gas line installation.

Inspections
When a building permit is required for an accessory structure, see inspections required as applicable.

Please call 801-208-3138 to schedule an inspection. Please call before 1 p.m. the day before you need an inspection, and have your permit number available.

Locations
Accessory structures are permitted uses in the single-family residential zoning districts. In other zoning districts site plan review and approval by the Planning Commission may be required.. Accessory structures must not be constructed over property easements, check with the Planning Department to see if your lot has easements. Generally, accessory structures on residential properties must be setback from property lines at least 5 feet, ,but there are exceptions and additional rules based on height and footprint size. Please see the Accessory Structure Ordinance, or the Garage and Shed Helps Diagram or contact the Planning Department for additional information.

Riverton City Ordinance 18.225 Accessory Structures

Area
On any lot, the combined floor area of the detached accessory building(s) and the primary Structure shall not exceed 30% of the entire lot area. Additionally the combined area of detached accessory structures may not exceed 10% of the total lot area.

Height
Detached accessory structures must not exceed 20 feet in height, except on lots of at least 10,000-sf , where structures may be up to 25 feet, but may not exceed the height of the main dwelling, Height is measured from finish grade to peak.

Materials
Exterior materials shall be in compliance with Riverton City Land Use Code 18.225.040.3. See the table below for guidance.

Architecture	See 18.225.040 Architectural standards. In the event of a discrepancy between this table and City Ordinance, the City Ordinance shall prevail.
0 to 200 sf	General appearance, building materials, and color, shall be consistent in color and design with the main dwelling. Exposed plywood or particle board, corrugated metal, or similar materials are prohibited as exterior materials.
201 to 1,200 sf (see note 1)	General appearance, building materials, and color, shall utilize only exterior building materials that are present on the main dwelling, excluding trim and non-architectural elements, structural materials, and prohibited materials. Colors shall be similar in tone and complementary to those used on the main dwelling. Wood or wood product siding, exposed plywood or particle board, corrugated metal, or similar materials are prohibited as exterior materials. Fiber-cement siding and aluminum or other metal siding may be substituted for vinyl siding if such siding is similar in color and appearance to the vinyl siding used on the main dwelling, as approved by the planning manager.
Over 1,200 sf (see notes 1 & 2)	Shall include a minimum of 20 percent of the front exterior walls, and of the street side(s) of a corner lot, in masonry such as brick or stone same type, coloring, and/or style as on the main dwelling.
Note 1 Houses of all brick	Where exterior materials on the main dwelling consist exclusively of masonry such as brick or stone, the exterior side of the accessory structure facing the front of the lot shall be entirely masonry of the same type and style on the main dwelling. For the remaining sides, the lower one-third of each side shall be masonry as used on the front elevation, and the remaining exterior may consist of stucco and/or vinyl or fiber-cement siding that is complementary to the main dwelling in color and design.
Note 2 Spilt-face block	On property of at least one acre and zoned RR-22, R-1, or A-5, split-face or honed block may be used in place of stucco or other materials, but may NOT be substituted for any required brick, stone or other masonry consistent with that used on the home.

Submittals Required for Permit

Site Plan – showing lot dimensions and locations of existing and proposed structure(s).
Floor Plan – Outside lines and dimensions of the structures, location of interior walls, size and spacing of footings, slabs, joist, rafters, headers, etc.
Cross Sections and/or Elevations – rear or side views showing:

Depth and type of footing and foundation
Material specifications for walls, roof and floors
Manner of construction

Plan Examples and Notes

Structural Recommendations
Foundations: The foundation for detached garage or shed up to 600 sq. feet, having a maximum wall height of 10 feet and a maximum width/length shall be no more than 30 feet may use the Riverton City approved monolithic drawing. All structures over 600 sq. feet or have wall heights exceeding 10 feet are required to use standard footing and foundation for support.
Framing: The following conventional framing methods are recommended for the construction of garages and shed.

Bottom plate to be one treated or foundation grade redwood 2” x 4” anchored by approved strap anchors of ½” x 10” bolts, with 3” x 3” plate washer and nut spaced not more than one foot from each corner or end of plate and 32” on center.
Studs (2” x 4”) spaced 16” on center, with three studs at exterior corners.
Top plate two (2” x 4”) lapped at corners and overlapped at least 24” at splices.
Wall sheathing panel sheathing (plywood, oriented strand board (OSB) is recommended. Structural hold downs must be attached to the studs and plates as per plans.
Manufactured trusses must be used if over 20 feet in lieu of rafters.

NOTE: This handout shall serve as a guide by which to lay out a new accessory building, but upon submitted plans to the Riverton City Building Department, the City approved job copy of the plans shall be referenced. This handout does not override comments made on your plan review.