ADUs are allowed in Boise CityTypes:DetachedInternal
Types:DetachedInternal
Accessory Dwelling Unit (ADU) Rules for Boise City, ID
Is your property eligible for an ADU?
# of Properties
73,576
Owner-occupied
77%
Zoning districts
30
Avg Home Value
$513,245
Median Lot Size
0.19 acres
Avg Income
$97,942
Residential Types:
73,576 housing units
Single Family
1%
Other
99%
Zoning Districts:
86,834 parcels · 30 districts
R-1C
60%(52,500)
R-2
12%(10,536)
R-1B
10%(8,298)
R-1A
4%(3,064)
Other
14%(12,436)
ADU Rules
What can you build in Boise City, ID?
Boise City, ID follows state and local rules for Accessory Dwelling Units. Here is a concise overview of the local rules.
Eligibility
- –Internal / Attached ADU: By Right
- –Detached ADU: By Right
Interior / Attached ADU Size Limits
- –Maximum size of 900 sq ft
- –Maximum size of 70% of the primary dwelling’s total floor area
Detached ADU Size Limits
- –Maximum size of 900 sq ft
- –Maximum size of 70% of the primary building's total floor area
Max Units
- –Single-family lots: max 2 accessory residential units per lot (any combination of ADUs or THOWs). Duplex, triplex, fourplex, and multifamily lots: 0 ADUs per lot.
Owner Occupancy
- –Owners must occupy either the principal residence or the ADU
Parking
- –No citywide minimum or maximum off-street parking for ADUs; Harris Ranch SP requires 1 space per ADU in addition to the principal dwelling (waivable by Planning Director); MX-5 Downtown exempt from minimum parking.
What's allowed on your lot?
These are the municipality-wide rules. What's allowed on a specific property also depends on state laws, setbacks, floor area ratio, lot coverage, environmental constraints, topography, and other property-specific factors. Search your address on FutureLot to see what's allowed on your property.
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ADU rules in other Idaho municipalities
Rules change at the town line. Check the municipality your property is actually in.
Ada County