ADU rules in Middletown

Detached backyard accessory apartments are expressly allowed. Zoning Code §4.11.3.3 lets an accessory apartment be 'attached to or located within' the principal dwelling 'or detached from' it and located on the same lot, and the Article VI accessory use schedules list 'Accessory Apartments (§4.11)' as a permitted accessory use in all seven residential zones (RPZ, R-15, R-30, R-45, R-60, R-1 and M) as well as the business, industrial and mixed-use zones. A detached unit must meet the yard, height and coverage numbers of the underlying zone (§4.11.3.5), so in R-15 that means 25 ft front, 30 ft rear and 10 ft side yards, 25 percent building coverage and 36 ft height. This is a reversal of the pre-2022 code, which required the unit to be inside or attached to the house with an eight-foot common wall and flatly barred conversions of garages or other auxiliary buildings; Ordinance Z2022-7 repealed those limits effective 12-7-2022.

Attached additions and interior conversions are allowed on the same footing as detached units under §4.11.3.3, which covers accessory apartments 'attached to or located within the proposed or existing principal dwelling'. The city's Application Forms page treats a 'New or Conversion' accessory dwelling unit as one $50 application. Zoning Code §3.9 goes further and carves accessory apartments out of the usual bar on enlarging a nonconforming use, so even a single-family dwelling that is itself nonconforming may be enlarged to accommodate one. Every attached-unit hurdle in the old code was repealed by Z2022-7: the eight-foot common wall, the mandatory interior connecting doorway, the ban on an additional front entrance, the requirement to share the house's utilities and meters, and the one-street-number rule are all gone.

Zoning Code §4.11.3.4 caps an accessory apartment at 1,000 sq ft of floor area and at 40 percent of the principal dwelling's floor area, whichever binds first; a 2,000 sq ft house is therefore limited to 800 sq ft. There is no minimum size any more (the pre-2022 code required at least 425 sq ft and capped the unit at 800 sq ft and 33 percent). The §1.15 definition requires the principal dwelling to be of greater square footage than the accessory apartment. Height, yards and lot coverage come from the underlying zone under §4.11.3.5 rather than from any separate ADU standard. Middletown's cap is more generous than the CGS 8-2o floor it opted out of, which would have required only the lesser of 30 percent or 1,000 sq ft.

No owner-occupancy requirement survives. The seven standards in §4.11.3 say nothing about who must live on the property, and the prior rule (old §4.11.3.1, carried forward from Zoning Code §12.14) that 'the principal unit and the accessory apartment shall remain under common and ownership and shall be owner occupied at all times' was struck by Ordinance Z2022-7, approved 11-28-2022 and effective 12-7-2022; the deletion is visible as strikethrough in the redline attached to the Common Council packet of 12-5-2022. This is purely a local repeal and not a state protection: CGS 8-2o never barred owner-occupancy mandates, and Middletown opted out of 8-2o entirely, so the Planning and Zoning Commission could restore an owner-occupancy rule by ordinary text amendment.

Section 4.11.3.6 defers to §4.19.4, which the 7-1-2026 housing and parking amendment (Z2026-4) rewrote to list 'Accessory Apartment' inside a single 'All Residential Uses' row. For residential uses of 16 or fewer dwelling units outside the Parking Management District, 'no off-street parking shall be required provided that the amount of off-street parking supplied will not result in a specific adverse impact to public health or safety'. Because a house plus one accessory apartment is two units, that zero-parking default is the normal case citywide. Inside the Parking Management District, a §2.30 overlay the city adopted as a 'conservation and traffic mitigation district' under Section 19 of Connecticut Public Act 25-1 and mapped in June 2026, the requirement is one space per studio or one-bedroom unit and two per unit with two or more bedrooms, and a developer may instead submit a parking needs assessment under §4.19.9. Check the June 2026 Zoning Map for whether a given address falls in the overlay. The old rules were stricter: one dedicated space per accessory apartment under Z2022-7, and before that three spaces for the house plus one for the apartment, all served by a single driveway.

Administrative, with no public hearing and no discretionary board vote. An accessory apartment is a permitted accessory use under the Article VI schedules and is processed as a site plan under §5.5. Section 5.5.3.2 puts 'all single and two-family detached dwellings or any addition or accessory uses thereto which meet all Code requirements' in Category 2, where proposals 'may be issued a certificate of zoning compliance by the Zoning/ Blight Enforcement Officer and need not go through the formal site plan review process'. Even read as Category 3, staff would decide it, since only proposals adding more than 5,000 sq ft of construction and more than 10 new parking spaces go to the Commission. The city's Application Forms page confirms the practice: an 'Accessory Dwelling Unit (New or Conversion)' uses the Site Plan Application Form with a $50 fee, one application copy, four 24 in. x 36 in. site plans for detached units, and one set of floor plans, plus a possible B100 health application on well and septic lots.

Section 4.11 imposes no occupancy, tenancy, family-relationship or rental-term limits, and with owner occupancy repealed a Middletown accessory apartment can simply be leased. It cannot be sold off separately: §1.15 defines an accessory apartment as a unit on the same lot as the principal dwelling and §4.11.3.2 allows only one per lot, so separating it would require a subdivision. Short-term rental is the genuinely unsettled part. Middletown's Code of Ordinances on eCode360 has no short-term rental or rental licensing chapter (searched 2026-08-05; the only rental-related chapters are Fair Housing, the Fair Rent Commission and Housing Standards), and the zoning code does not list 'Tourist Home' as a permitted or special-exception use in any residential zone. The nearest analogue is the Bed and Breakfast special exception under §5.6.8.31, available only in the RPZ zone on lots of record under 10,000 sq ft, which requires an owner-occupied residence, no more than five guest rooms, stays no longer than two consecutive weeks, and an annual permit from the Zoning/Blight Enforcement Officer. Ask the Land Use department before advertising an accessory apartment nightly.