ADUs are allowed in Idaho SpringsTypes:DetachedInternal
Types:DetachedInternal
Accessory Dwelling Unit (ADU) Rules for Idaho Springs, CO
Is your property eligible for an ADU?
# of Properties
31
Owner-occupied
71%
Zoning districts
17
Avg Home Value
$134,632
Median Lot Size
0.19 acres
Avg Income
$89,016
Residential Types:
31 housing units
Residential
100%
Zoning Districts:
2,401 parcels · 17 districts
R-1
45%(1,087)
C-1
12%(285)
R-2
12%(277)
C-2
10%(235)
Other
22%(517)
ADU Rules
What can you build in Idaho Springs, CO?
Idaho Springs, CO 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
Size Limits
- –Maximum size is the greater of 750 sq ft or 50% of the principal building’s gross floor area.
Max Units
- –1 ADU per main dwelling
Parking
- –1 space/ADU; required only if all of: no off-street parking on the parcel, zoning requires one or more spaces for the primary dwelling, and on-street parking is prohibited on the block; otherwise none. Fee‑in‑lieu: $2,500 per required space within the boundary.
Rental Restrictions
- –Short-term rentals (<30 days) allowed only if the ADU is the operator's primary residence; license required and capped at 15 citywide.
ADU State Law
What can you build in Colorado?
- –ADUs must be approved based on objective standards; no discretionary hearings allowed.
- –Historic properties: Local historic review may still apply in designated historic districts.
- –Exempt parcels: ADUs are not required to be allowed on parcels without adequate water/sewer, in floodways, or on certain historic properties.
- –HOAs cannot prohibit ADUs: HOA rules that conflict with the state ADU law are void.
- –Parking exceptions exist: In rare cases, one parking space may be required if there is no existing off-street parking and on-street parking is prohibited.
- –Local rules still matter: Building code, fire code, utility capacity, and life-safety standards still apply.
- –More permissive is allowed: Municipalities may allow larger ADUs, multiple ADUs, or additional housing types beyond what the state requires.
- –Local zoning controls whether ADUs are allowed at all.
- –HOA rules may still apply.
- –More permissive local rules are allowed.
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 Colorado municipalities
Rules change at the town line. Check the municipality your property is actually in.
Clear Creek County