ADUs are allowed in FairfieldTypes:DetachedInternal
Types:DetachedInternal
Accessory Dwelling Unit (ADU) Rules for Fairfield, CT
Is your property eligible for an ADU?
# of Properties
20,218
Owner-occupied
83%
Zoning districts
18
Avg Home Value
$655,603
Median Lot Size
0.25 acres
Avg Income
$180,902
Residential Types:
20,218 housing units
Single Family
79%
2-3 Family
6%
Apts (4+ units)
1%
Other
14%
Zoning Districts:
24,283 parcels · 18 districts
A
28%(6,892)
B
18%(4,268)
R-3
15%(3,571)
DRD
14%(3,284)
Other
26%(6,268)
ADU Rules
What can you build in Fairfield, CT?
Fairfield, CT 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 size of 40% of the originally existing residence or 1,500 sq ft, whichever is less
Detached ADU Size Limits
- –Maximum size of 40% of the area of the existing main dwelling or 1,500 sq ft, whichever is less (exclusive of utilities)
Max Units
- –Single-family: 1 ADU per lot (AAA/AA/R-3: 1 attached or 1 detached; R-2/A/B/C: attached only).
- –Two-/multifamily: 0.
Owner Occupancy
- –Principal owner must occupy the primary dwelling or the ADU
Parking
- –1 off-street space per ADU; no max; no ADU-specific exceptions
Rental Restrictions
- –Min rental term 60 days; no rentals <60 days (primary or ADU).
- –If designated affordable (CGS 8-30g): tenant primary residence, <=80% SMI, rent caps, 10-year deed restriction.
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.
Greater Bridgeport County