ADUs are allowed in BerlinTypes:Internal
Types:Internal
Accessory Dwelling Unit (ADU) Rules for Berlin, CT
Is your property eligible for an ADU?
# of Properties
7,487
Owner-occupied
88%
Zoning districts
34
Avg Home Value
$234,625
Median Lot Size
0.43 acres
Avg Income
$121,441
Residential Types:
7,617 housing units
Single Family
81%
2-3 Family
4%
Apts (4+ units)
4%
Condos
12%
Zoning Districts:
9,120 parcels · 34 districts
R-15
23%(2,129)
R-11
17%(1,588)
R-21
15%(1,377)
R-43
11%(1,029)
Other
33%(2,997)
ADU Rules
What can you build in Berlin, CT?
Berlin, CT follows state and local rules for Accessory Dwelling Units. Here is a concise overview of the local rules.
Eligibility
- –Internal / Attached ADU: Special Permit
- –Detached ADU: Not permitted
Interior / Attached ADU Size Limits
- –Maximum size of 700 sq ft for internal or attached ADUs (including up to 150 sq ft of minor additions)
Owner Occupancy
- –Owner must reside on premises; annual occupancy certification required.
Parking
- –2 off-street/ADU; Commission may modify; on-street/shared/off-site allowed within 500 ft (on-street counts as 2)
Rental Restrictions
- –If 55+ occupancy is waived (internal/attached): rent capped at ≤30% of 80% AMI (2-person)
ADU State Law
What can you build in Connecticut?
- –Connecticut Public Act 21-29 (now CGS § 8-2o) established statewide ADU rules.
- –115 municipalities opted out of the state ADU provisions. In those towns, ADUs may still be allowed, but they are regulated solely under local zoning bylaws.
- –54 municipalities did not opt out and are subject to the state's default ADU standards. Local bylaws in these towns must allow at least the minimums required by state law.
- –At least one accessory apartment must be allowed as of right on any lot with a single-family home.
- –Towns must allow an ADU to be at least the lesser of 1,000 sq ft or 30% of the principal dwelling's Net Floor Area.
- –Setbacks, lot size, building frontage, lot coverage, height, and design requirements cannot be more restrictive than those applied to the principal dwelling.
- –Only one parking space can be required per ADU.
- –A passageway between units
- –A separate exterior entrance (unless required by code)
- –A relationship (e.g. familial or employment) between occupants
- –Age minimums for ADU tenants
- –Separate utility billing
- –Periodic permit renewals
- –Owner-occupancy is not required under state law, but towns may impose it.
- –Towns may regulate short-term rentals.
- –Requirements for wells or private sewerage systems still apply, but approval cannot be unreasonably withheld.
- –Towns may not condition ADU approval on fixing unrelated nonconformities on the lot.
- –No new utility connection fees may be charged unless the ADU is built with a new principal dwelling.
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 Connecticut municipalities
Rules change at the town line. Check the municipality your property is actually in.
Capitol County