ADU rules in Fairfield

Detached (free-standing) accessory apartments are allowed only in the Residence AAA, AA, and R-3 zones. Section 3.2's use table confirms the limit, listing 'Accessory Dwelling Units (Detached)' as an accessory permitted use under AAA, AA, and R-3 while leaving the R-2 and A columns blank. Section 13.3.H adds gates that bite on older lots: the lot must meet the applicable zone's minimum lot area (so a legally nonconforming undersized lot is disqualified), the structure must meet the setbacks and other design requirements that apply to primary structures rather than to accessory buildings, and the primary structure must not already contain an accessory apartment. Detached units are unavailable in the Residence R-2 and A zones, in the multi-family B and C districts (where Section 5.2.2.C allows attached units only), and in the Beach District. The Town Plan and Zoning Commission loosened this on 3-22-2022 by striking an older two-acre minimum lot requirement and substituting the applicable zone's minimum lot area.

Section 13.3 lets a one-family residence located within lawful setbacks in the AAA, AA, A, R-3, R-2, B, and C zones be converted into a one-family dwelling with a single accessory apartment, and Section 3.2's use table lists 'Accessory Dwelling Units (Attached)' as an accessory permitted use in all five single-family districts (AAA, AA, R-3, R-2, A). Interior conversions, basement units, and additions all qualify, and Section 13.3.C even allows the apartment's entrance on the front facade provided it is separated from the existing front door by at least 10 feet, the house keeps the appearance of a single-family dwelling, and any fire escape or outside stairway is enclosed. In the multi-family Residence B and C districts, Section 5.2.2.C narrows the allowance to lots that meet the minimum lot requirements and that contain only a single-family residence. The Beach District is the one residential district with no accessory apartment allowance at all: Section 4.2 permits no use there except those its own list provides, and bars detached accessory structures from containing finished livable floor area, plumbing fixtures, or heat.

The same cap governs attached and detached units. Section 13.3.B sets it for a conversion of the residence itself; Section 13.3.H.3 repeats it for a free-standing structure, there measured against 'the area of the existing main dwelling' and stated as exclusive of utilities. Because the percentage is keyed to the originally existing residence, enlarging the house afterward does not enlarge the allowance. Only one accessory apartment is permitted per residence, and under Section 13.3.H.5 a detached unit is unavailable if the primary structure already contains one. Fairfield's cap is more generous than the state floor in CGS 8-2o(a)(3) (the lesser of 30% of the principal dwelling's net floor area or 1,000 square feet), which the town is not bound by in any case because it opted out of the statute in 2022.

Section 13.3.A requires a principal owner of the residence to live in either the primary dwelling or the accessory apartment 'throughout the duration of the permit,' making this an ongoing condition rather than a one-time test at application. Section 13.2 defines a principal owner as an owner of not less than a 50% interest in the residence, so co-ownership arrangements need to clear that threshold. Section 13.6 enforces the rule across sales: a new owner must file a notice with the Zoning Enforcement Officer within 30 days of taking title stating whether they intend to continue the accessory apartment use, and any continued use remains subject to all of Section 13. Section 13.5 lets the Commission revoke the permit on a finding of non-compliance with Section 13.3. CGS 8-2o never prohibited local owner-occupancy mandates (they are absent from the list of forbidden requirements in 8-2o(a)(6)), and Fairfield opted out of the statute regardless.

Section 13.3.D states that the number of off-street parking spaces for the accessory apartment 'shall be not less than one,' phrasing that sets a floor rather than a ceiling. The off-street parking schedule at Section 25.4.1.K, amended 3-3-2026, lists 'Accessory Dwelling Unit, 1 space' among the ratios for properties with dwelling units up to 16 units, though that row is introduced as 'Recommended as follows' while the schedule's column header reads 'Minimum Number of Spaces.' Fairfield did opt out of the old statewide cap on dwelling-unit parking at CGS 8-2(d)(9), using the CGS 8-2p mechanism, in the same 5-23-2022 RTM resolution that opted out of the accessory apartment statute, but that is history without continuing statutory basis: Nov. Sp. Sess. P.A. 25-1, S. 53 repealed 8-2p effective 1-1-2026, and S. 18 rewrote 8-2(d)(9) effective 7-1-2026 so that zoning regulations may not 'require a minimum number of off-street motor vehicle parking spaces for any residential development except as provided in section 8-3n.' New CGS 8-3n (P.A. 25-1, S. 19, effective 7-1-2026) reserves mandatory minimums to developments of more than sixteen dwelling units and bars any commission or zoning enforcement officer from rejecting a residential application solely for failing to meet a parking requirement unless it finds a specific adverse impact on public health and safety that approval conditions cannot mitigate. So the one-space figure remains Fairfield's written rule and is what an applicant should plan for, but since 7-1-2026 it is not independently enforceable against a one-unit accessory apartment as a ground of denial absent that finding. See the 2026 supplement to chapter 124 at https://www.cga.ct.gov/2026/sup/chap_124.htm.

Approval is administrative. Section 13.4 provides that no conversion may occur and no associated building permit or certificate of occupancy may issue until the owner 'has received a written permit from the Zoning Enforcement Officer.' There is no special permit, special exception, or public hearing; Section 3.2's use table classifies accessory dwelling units as 'A = Accessory Permitted Use' rather than 'SE = Special Exception Use.' The submission is an affidavit on a form supplied by the Zoning Enforcement Officer, architectural drawings or clear photographs showing the proposed exterior alterations, and interior floor plans showing the floor area of the proposed apartment and of the primary dwelling. Standard zoning compliance applications are filed through the town's online CitySquared portal. The permit stays conditional: Section 13.5 lets the Commission revoke it on a finding of non-compliance with Section 13.3.

Section 13.3.E carries the operative rule: 'Neither the existing house or the accessory apartment can be rented for a period of less than 60 consecutive days,' which forecloses short-term and vacation rental of either unit on any property with an accessory apartment. The same subsection caps occupancy of the apartment at two persons, rising to three only where the unit is contracted with the Town of Fairfield or its designated agent as an 'affordable housing' unit. Conventional long-term tenancy is the expected use, subject always to the standing owner-occupancy requirement, and Section 13.3.G offers an optional affordable-housing track under CGS 8-30g requiring a recorded 10-year deed restriction, a tenant whose income is at or below 80% of the State Median Income, and owner certification before initial occupancy, by January 31 each year, and on each change of tenant. The apartment is an accessory use on the same lot as the house, so it cannot be sold separately. Fairfield's town code has no short-term rental licensing ordinance; Chapter 87 (Rental Property), adopted 6-26-2023, establishes a Fair Rent Commission, not a rental-registration regime.