ADUs are allowed in DillonTypes:DetachedInternal
Types:DetachedInternal
Accessory Dwelling Unit (ADU) Rules for Dillon, CO
Is your property eligible for an ADU?
# of Parcels
1,565
Zoning districts
10
Avg Parcel Value
$1,031,869
Zoning Districts:
1,565 parcels · 10 districts
RH
49%(773)
CA
14%(221)
MU
12%(191)
RM
12%(182)
Other
13%(198)
ADU Rules
What can you build in Dillon, CO?
Dillon, 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 internal ADU size of one-third of the primary dwelling’s heated living area (single-family or duplex).
Max Units
- –Single-family: 1 ADU per lot; Duplex: 1 per primary unit, up to 2 per lot.
- –Townhouse/multifamily or zones C/CA/MU/RH/POS/UR: 0 per lot.
Parking
- –2 spaces per ADU (off-street); on-site; plan required; no in-lieu fees; denial if two spaces with snow storage are not provided
Rental Restrictions
- –Six-month minimum rental term for ADUs (waivable for good cause if occupant works in Summit County at least 30 hours/week); short-term rentals under six months prohibited; rentals may not begin until certificate of occupancy, inspections, tap fees paid, and deed restrictions recorded
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.
Summit County