ADUs are allowed in FrederickTypes:DetachedInternal
Types:DetachedInternal
Accessory Dwelling Unit (ADU) Rules for Frederick, CO
Is your property eligible for an ADU?
# of Properties
10,300
Owner-occupied
91%
Zoning districts
18
Avg Home Value
$557,979
Median Lot Size
0.16 acres
Avg Income
$124,208
Residential Types:
10,300 housing units
Residential
100%
Zoning Districts:
29,576 parcels · 18 districts
R-1
77%(22,861)
R-2
5%(1,540)
R-MH1
4%(1,304)
R-E
3%(831)
Other
10%(3,040)
ADU Rules
What can you build in Frederick, CO?
Frederick, 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
Interior / Attached ADU Size Limits
- –Maximum ADU size: for single-family detached, the greater of 800 sq ft or 50% of the principal building’s total floor area, capped at 1,000 sq ft; otherwise 1,000 sq ft
Detached ADU Size Limits
- –Maximum size for ADUs accessory to a single-family dwelling: greater of 800 sq ft or 50% of the principal building’s floor area, capped at 1,000 sq ft
Max Units
- –Single-family detached: 1 ADU/lot
- –Religious place of assembly: 1 ADU/lot
- –Storage facility (on-site security employee): 1 ADU/lot
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.
Weld County