ADU rules in Syracuse

Table 3.1 lists "Accessory dwelling unit, Detached" as an allowed accessory use (A) in R1, R2, R3, R4 and R5 and in MX-1, MX-2 and MX-3, and gives it no designation at all in MX-4, MX-5, CM, LI or OS. The condition that bites is § 3.4D(1)a.ii: an ADU is allowed only on a lot with an owner-occupied Single-Unit Detached dwelling in the Residential Living Use Category, so two-unit houses, rowhouse-style single-unit attached dwellings and landlord-owned rentals are shut out entirely. Only one ADU is allowed per property or lot of record whether attached or detached, a detached unit must sit to the side or rear of the house, and no ADU may sit forward of the front façade of the primary dwelling. Within those limits the approval itself is administrative: Minor Site Plan Review decided by the Zoning Administrator, no hearing.

"Accessory Dwelling Unit, Attached" carries the same A designation in R1 through R5 and MX-1 through MX-3, and is subject to the same eligibility gate: only on a lot with an owner-occupied single-unit detached house. § 3.4D(1)b.i defines attached as at least 25 percent of the ADU's total wall area, or its floor or ceiling, fully connected to a wall, floor or ceiling of the principal residential structure, which covers basement, attic, addition and internal conversions. Because only one ADU is allowed per lot, an internal unit and a backyard cottage cannot coexist. Every ADU must have a separate exterior entrance and contain cooking, sleeping and sanitary facilities, may have only one kitchen (partial or full), and any outside access stairway must be off the street-facing façade.

§ 3.4D(1)c.5 caps the gross floor area of any ADU at 800 square feet "even when combined with a non-residential structure," and c.7 adds that no ADU may exceed 50 percent of the heated floor area of the principal structure and "in no case shall exceed 800 SF." On a 1,200 square foot house the effective cap is therefore 600 square feet, not 800. § 3.4D(1)b.iv allows only one bedroom. Height comes from the accessory-structure column of the district tables: 16 feet to the peak of the roof in R1, R2 and R3 (Tables 2.2 to 2.4) and 25 feet in R4 and R5 (Tables 2.5 and 2.6), which effectively rules out a full two-story detached ADU in the lower-density districts. Two more envelope limits apply: § 3.4C(6) caps the combined gross floor area of a detached ADU plus any non-residential accessory structures (a garage, for example) at 1,000 square feet in residential districts, and § 3.4D(1)c.8 holds the combined footprint of house, ADU and other accessory structures to the district's maximum structural coverage, 30 percent in R1 through R3.

Two provisions impose it. § 3.4D(1)a.ii allows ADUs "only on lots with owner-occupied Single-Unit Detached dwellings in the Residential Living Use Category," and § 3.4D(1)e.ii requires the owner to "reside in either the Primary Dwelling Unit or the Accessory Dwelling Unit as the owner's primary place of" (the adopted sentence ends there; the evident meaning is primary place of residence). This is an ongoing requirement, not a one-time test at application, and it is reinforced structurally: § 3.6A(1) defines the Residential Living category around occupancy of an owner-occupied dwelling unit, so a property that stops being owner-occupied falls into the Residential-Commercial category, where § 3.4D(1)a.ii permits only legal pre-existing nonconforming ADUs to continue, subject to the nonconformity limits in § 1.5. New York has no statewide ADU statute preempting local owner-occupancy rules, so nothing overrides this.

Table 4.1 (Required Off-Street Parking Spaces) lists "Accessory dwelling unit" at "None required," the same as single-unit detached and single-unit attached dwellings; only two-unit and multi-unit dwellings carry a ratio (0.5 space per unit). There is no transit-proximity test and no lot-size trigger that adds a space. The related constraint is physical rather than numerical: § 3.4D(1)b.v bars the structure housing a detached ADU from being served by a driveway separate from the one serving the primary dwelling, except to take a new access from an alley. Table 4.1 minimums are switched off entirely for lots of 5,000 square feet or less and for all development in MX-5 (§ 4.4B(3)), which matters for the small city lots common in Syracuse.

§ 3.4D(1) requires Minor Site Plan Review for every ADU "in all zone districts as allowed per Table 3.1," and Minor Site Plan Review is an administrative approval: Table 5.1 shows Staff as the decision maker with no required public hearing and no mandatory notice, and § 5.4A(3)c states that the Zoning Administrator "shall review the minor site plan application and render a decision." Applications are filed through the city's online portal linked from the Office of Zoning Administration page. Two things can pull it out of the staff lane: under § 5.4A(2)b.ii the Zoning Administrator may refer an application to the City Planning Commission, and any referred minor site plan must then have a public hearing; and Table 5.1 note [3] requires Syracuse Landmark Preservation Board review where the property is on the Historic Properties List. No building permit issues until the site plan is approved (§ 5.4A(5)b), and appeals of the administrative decision go to the Board of Zoning Appeals.

Nothing in § 3.4D(1) prohibits renting the unit, and the arrangement the section contemplates is an owner living in one of the two units while the other is occupied by someone else; § 3.4D(1)e.ii only requires that the owner occupy the primary dwelling or the ADU. Separate sale is expressly barred: § 3.4D(1)e.i says ownership of the ADU "may not be legally severed from ownership of the associated lot nor from any other structures on the lot." Short-term letting is blocked by the use definitions rather than by any short-term rental ordinance: § 3.6A(1) defines Residential Living around occupancy "for 30 or more consecutive days," § 3.6A(2) states that lodging uses with tenancy under thirty days are classified in the Commercial Lodging category, and Table 3.1 gives that category no accessory-use status alongside a house. The only owner-occupied lodging option is a Bed and Breakfast or Inn (special use permit in R2 to R4, permitted in R5 and MX-1 to MX-5), and § 3.3C(5)a requires it to be "the sole accessory use to the principal residential use," so it cannot be combined with an ADU. Syracuse's Rental Registry (Revised General Ordinances § 27-130 and § 27-131) reaches one- and two-family non-owner-occupied dwellings, so on its face it does not capture an owner-occupied ADU property, but confirm with the Division of Code Enforcement before renting.