ADU Zoning in Fairfield, Connecticut
What Fairfield allows for accessory dwelling units — permitted zones, size limits, parking, rental rules and utilities. Boxx ADUs designs and builds ADUs in Fairfield and across Fairfield County. Call us to talk through your property, or send us a message.
Which zones allow ADUs?
Attached ADUs: Permitted as an accessory use in Single-Family Residence Districts (AAA, AA, R-3, R-2, and A) and Multi-Family Residence Districts (B and C).
Detached ADUs: Permitted as an accessory use only in Single-Family Residence Districts AAA, AA, and R-3.
What are the size/floor area requirements?
The ADU cannot exceed 40% of the originally existing residence's floor area or 1,500 square feet, whichever is less.
How many parking spaces?
At least one off-street parking space is required specifically for the ADU.
What are the rental requirements?
Neither the primary house nor the ADU can be rented for a period of less than 60 consecutive days.
Occupancy is limited to a maximum of two persons, unless the unit is contracted as “affordable housing,” in which case up to three persons may occupy it.
A principal owner (holding at least 50% interest) must reside in either the primary dwelling or the ADU for the duration of the permit.
What about utilities, sewer or septic?
If public water and sewer are unavailable, private systems must be approved by the Department of Health. The unit must comply with all housing, building, fire, and health codes.
Summarized for convenience and current as of publication. Local regulations change — confirm details with the town before relying on them.