MAXIMUM NUMBER AND SIZE

General17

RC, R-1, R-4, R-6, R-8, R-10, and R-14

1 ADU is permitted per legal lot.

Unit size shall be determined by lot size and the size of the primary structure; the total gross floor area of the ADU shall not exceed the size stated in the Maximum Unit Size section of this table or 75% of the total gross floor area of the primary structure, whichever is smaller.41

MAXIMUM UNIT SIZE

Lot Area:

Maximum ADU Size40, 41

3,000 sq. ft. or less

600 sq. ft.

3,001 – 4,999 sq. ft. or less

700 sq. ft.

5,000 – 6,999 sq. ft. or less

800 sq. ft.

7,000 – 8,999 sq. ft. or less

900 sq. ft.

Greater than 9,000 sq. ft.

1,000 sq. ft.

MAXIMUM WALL PLATE HEIGHT10, 18, 19, 41

RC, R-1, R-4, R-6, R-8, R-10 and R-14

ADUs are subject to the maximum wall plate height of RMC 4-2-110A, and associated conditions and shall not be taller than the primary structure. Additional ADU height allowances may be permitted upon application and approval of a modification pursuant to RMC 4-9-250.42

LOCATION

General

RC, R-1, R-4, R-6, R-8, R-10 and R-14

ADUs shall be located at least 4 ft. from any residential structure.

MINIMUM SETBACKS4, 41

Front Yard and Secondary Front Yard

RC, R-1, R-4, R-6, R-8, R-10 and R-14

The ADU shall be set back an additional 5 ft. parallel to and measured from the front facade of the primary structure and shall comply with the setbacks applied to the primary structure, as identified in RMC 4-2-110A, Development Standards for Residential Zoning Designations.

ADUs shall not be permitted between the primary structure and the street unless approved in the Conditional Use Permit process.

Side Yard

RC and R-1

25 ft.

R4, R-6 and R-8

5 ft.

R-10 and R-14

4 ft.

Rear Yard

RC, R-1, R-4, R-6, R-8, R-10 and R-14

5 ft.

When located within 10 ft. of the rear property line, at least 25% of the lineal length of the rear yard shall remain unoccupied from accessory dwellings, except when the rear property line abuts an alley.

Clear Vision Area

RC, R-1, R-4, R-6, R-8, R-10 and R-14

In no case shall a structure over 42 in. in height intrude into the 20 ft. clear vision area defined in RMC 4-11-030.

CRITICAL AREAS

General

RC, R-1, R-4, R-6, R-8, R-10 and R-14

See RMC 4-3-050, Critical Areas Regulations, and 4-3-090, Shoreline Master Program Regulations.