ADU rules in Roswell

Roswell's zoning ordinance has no "accessory dwelling unit" category at all. The one ADU-like use is "multi-generational housing", and it is a special use in only three of the seven residential districts: R-S Rural Suburban (art. 6, § 2.B.17), R-VL Residential Very Low (art. 8, § 2.B.9) and R-L Residential Low (art. 10, § 2.B.4). A special use means a development-plan application and a public hearing before the Planning and Zoning Commission (art. 3, § 8), and the unit is limited to relatives and to under 400 square feet. In R-1, R-2, R-3 and R-4 the use is not listed, and art. 52, § 3.A allows only one principal building per lot outside R-3 and R-4, so the only detached second dwelling in those districts is the grandfathered allowance at art. 12, § 2.A.4 for lots whose dwelling was built before January 1, 2010 and sits 75 feet or more back from the front property line.

The codified definition of multi-generational housing does not distinguish attached from detached, so an attached or internal unit under 400 square feet qualifies on the same special-use footing in R-S, R-VL and R-L; the adopting ordinance was explicit that "This housing may be an unattached, or attached to the primary unit" (Ord. No. 17-14, § 1.A, adopted 6-8-2017), wording Municode's codified text drops. Nothing in the code creates a general basement, garage or internal-conversion right: R-1 permits one "single-family detached dwelling per lot" (art. 12, § 2.A.1), and its only second-unit allowance, art. 12, § 2.A.4, requires a "second detached residential structure". Art. 50, § 2 note C counts a "half-story containing independent living quarters or apartment" as a full story for setback purposes, but that is a measurement rule, not a use permission.

The two paths have opposite size thresholds. Multi-generational housing is defined as an accessory residential unit "which is less than 400 square feet in size" (art. 4, § 2); the adopting ordinance said "no greater than 400 square feet" (Ord. No. 17-14, § 1.A), so treat 400 square feet as the ceiling and ask staff whether exactly 400 counts. The R-1 grandfather allowance runs the other way and requires a "second detached residential structure greater than 400 square feet in area" (art. 12, § 2.A.4). Either way art. 52, § 4.A.3 caps an accessory structure at no more floor area than the principal structure it serves, no taller than that principal building, and no more than 40 percent of the required rear yard setback area; maximum height in every residential district is 35 feet (art. 50, § 2).

No provision of the zoning ordinance requires the owner to live on the property, at application or on an ongoing basis. The binding limit is a family test rather than an ownership test: "multigenerational" is defined as "any number of persons related by blood, common ancestry, marriage, guardianship or adoption" (art. 4, § 2), so the unit is for relatives rather than for the open rental market. The R-1 grandfather allowance separately requires the two structures to stay "under one property ownership" (art. 12, § 2.A.4), which blocks a separate sale but does not require an owner in residence. The one place the city does impose a residency test is short-term rental registration, where the city's short-term rental page requires the STR to be in the host's primary residence.

Art. 52, § 7.F.16 sets the residential standard at "Two per dwelling unit", with no accessory-unit discount, no transit exemption and no small-unit exemption; the only carve-outs from the parking table are the C-3 and C-4 districts and property in the adopted Railroad District Metropolitan Redevelopment Area, none of which are residential districts. The R-1 grandfather allowance repeats the requirement on its face, demanding "a minimum of two paved off-street parking spaces for each unit with access to the street or an existing paved alley" (art. 12, § 2.A.4). Required spaces must sit within the property lines of the lot they serve (art. 52, § 7.A).

It turns entirely on the zone. A new multi-generational unit in R-S, R-VL or R-L is a special use: an application with a development plan, then a public hearing before the Planning and Zoning Commission, which may attach conditions and must find the use conforms to the city's land use plan (art. 3, § 8, as rewritten by Ord. No. 23-04 of 4-13-2023). The R-1 grandfather second structure at art. 12, § 2.A.4 is a permitted use, so it needs only staff review plus building permits. Building permits and inspections are run by the city's own Building Inspections office, with applications through the CloudPermit portal; accessory structures of 200 square feet or less that need no building permit still need a placement permit (art. 52, § 4.A.2.e). Since January 1, 2026 the state Construction Industries Division, not the city, issues electrical permits and does electrical inspections in Roswell.

A multi-generational unit may lawfully house only persons "related by blood, common ancestry, marriage, guardianship or adoption" (art. 4, § 2), which rules out renting it to an unrelated tenant; the adopting ordinance also made the permit "subject to administrative renewal every three (3) years demonstrating compliance with the definition" (Ord. No. 17-14, § 1.B), a condition the codified special-use lists no longer carry. The grandfathered R-1 second detached structure (art. 12, § 2.A.4) carries no occupancy limit and can be rented long term, but the lot must stay "under one property ownership", so the unit cannot be sold off separately. On short-term rentals the city is explicit that "ADUs may not be used as separate short-term rentals. They have the same limitations as the primary residence", and an STR must be in the host's primary residence, registered for $35, licensed as a business, insured, inspected by the fire marshal and building inspector, HOA-approved where applicable, and remitting 5 percent lodgers' tax monthly. No short-term rental chapter appears in the codified Code of Ordinances; the regime runs through business licensing and the lodgers' tax article (ch. 23, art. I).