ADUs are allowed in CentennialTypes:DetachedInternal
Types:DetachedInternal
Accessory Dwelling Unit (ADU) Rules for Centennial, CO
Is your property eligible for an ADU?
# of Properties
37,458
Owner-occupied
86%
Zoning districts
35
Avg Home Value
$745,920
Median Lot Size
0.21 acres
Avg Income
$145,055
Residential Types:
37,458 housing units
Single Family
91%
Other
9%
Zoning Districts:
41,160 parcels · 35 districts
NC6
34%(14,101)
NC9
25%(10,355)
NCSFA
10%(4,196)
NC5
7%(3,041)
Other
23%(9,467)
ADU Rules
What can you build in Centennial, CO?
Centennial, 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 of 50% of the principal dwelling’s footprint.
Detached ADU Size Limits
- –Maximum detached ADU size is 50% of the principal home’s footprint; only habitable ADU area counts (garage area excluded).
Max Units
- –Single-family detached: 1 ADU/lot (attached or detached)
- –Duplex or multifamily: 0 (not permitted)
Owner Occupancy
- –No owner-occupancy required; non-occupied ADU must be registered.
Parking
- –1 space/ADU; no max; reductions/credits may apply: on-street/public lot credits in AC/UC/TNDs; 2-space reduction for each car-share; up to 5% reduction for bicycle amenities; shuttle-to-light-rail provisions
Rental Restrictions
- –STR regulated under Article 9; if neither unit is owner-occupied, the owner must register the ADU before occupancy and renew annually.
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.
Arapahoe County