ADUs are allowed in Unincorporated AdamsTypes:DetachedInternal
Types:DetachedInternal
Accessory Dwelling Unit (ADU) Rules for Unincorporated Adams, CO
Is your property eligible for an ADU?
# of Properties
22,723
Owner-occupied
81%
Zoning districts
35
Avg Home Value
$571,709
Median Lot Size
0.19 acres
Avg Income
$106,213
Residential Types:
22,723 housing units
Single Family
7%
2-3 Family
1%
Apts (4+ units)
1%
Other
91%
Zoning Districts:
31,493 parcels · 35 districts
R-1-C
36%(11,426)
P-U-D
20%(6,345)
A-3
13%(4,125)
A-1
10%(3,004)
Other
21%(6,593)
ADU Rules
What can you build in Unincorporated Adams, CO?
Unincorporated Adams, 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
Parking
- –1 space per ADU; up to 25% of the minimum may be met by adjacent on-street parking; ADA, vanpool/carpool, alt-fuel, adjacent on-street, and structured/underground/within-building spaces do not count toward the maximum.
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.
Adams County
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