QUICK VIEW Spokane County ADU Requirements
Spokane County has different requirements for ATTACHED versus DETACHED ADU’s*
UNDER VERIFICATION WITH SPOKANE COUNTY*
Bedroom Count: 2 Bedrooms
Bathroom Count: 1 Bathrooms
Kitchen Count: 1
Heating Source: Separate
Entry Door: 36″
ADU’s per Parcel: 1
Off Street Parking Requirement:
Detached ADU: 1 parking spot required if Conditional Use Permit is required (Low Density Residential, Low Density Residential Plus, Medium Density Residential and High Density Residential)
Attached ADU: 1 parking spot required
Prohibitions:
Duplex/Multifamily/Existing ADU: Detached ADU not allowed for a duplex or another ADU
Lot Size: Detached ADU lot size 10,000 s.f. plus required if Conditional Use Permit required.
Conversion of Existing to ADU: Yes
ADU’s Allowed in Following Zones:
Detached ADU’s: Rural 5, Rural Traditional, Rural Activity Center, Urban Reserve Zones (note special zoning exemptions)
Attached ADU’s: Rural 5, Rural Traditional, Rural Activity Center, Urban Reserve Zones, Low Density Residential, Low Density Residential Plus, Medium Density Residential, High Density Residential, Large Tract Agricultural, Small Tract Agricultural, Forest Lands
Special Requirements:
1.CCR’s may restrict ADU’s
2.Detached ADU’s in Other Zones: Conditional Use Permit required for: Low Density Residential, Low Density Residential Plus, Medium Density Residential, High Density Residential. 10,000 s.f. lot required for Conditional Use Permit
Homeowner Residency Requirement: No requirement for homeowner to reside in primary home
Primary/ADU for Rental: No restriction on renting both the primary and ADU for rental purposes
Detached ADU’s:
Measured From: Exterior Walls
Main Floor Size: 800 s.f.
Second Floor Size: Up to 800 s.f. so long as 2 bedroom count is not violated
Basement Allowed: Yes-staircase from main floor to basement is not counted in total square footage for main floor
Attached ADU’s:
Measured From: Interior Walls
Main Floor Size: 900 s.f.
Second Floor Size: Yes, so long as the 900 s.f. total or 35% of the primary home requirement is met
Basement Allowed: Yes-staircase from main floor to basement is not counted in total square footage for main floor
Garages: Not counted in square footage calculations so long as 8′ wide door is installed
In General: Per underlying zoning requirement
Distance from Primary Homes: 150′ for detached unit
Front Setback: Per underlying zoning requirement
Back Setback: Per underlying zoning requirement
Sides Setback: Per underlying zoning requirement
Alleyway Setback: Per underlying zoning requirement
Singles Story ADU:
Wall Height: No restriction
Roof Height: 24′
Roof Pitch: 4/12 pitch
Two Story ADU:
Wall Height: No restriction
Roof Height: 24′
Roof Pitch: 4/12 pitch
45 Deg. Setback Required: No
Over Garage ADU:
Wall Height: No restriction
Roof Height: 24′
Roof Pitch: 4/12 pitch
45 Deg. Setback Required: No
Architectural Requirements: Attached ADU must Substantially match the primary home. Main door Must be located on side or back of ADU.
ADU Permit Process: Application and building permit
Special Hearing Requirement: Conditional Permit typically takes 60 to 90 days
Permit Cost: Calculated at Building Department
NA