Smithtown, NY Accessory Structures: Shed & Carport Rules (2026)

Section 112-10(A) of the Building Construction chapter generally requires a separate building permit before erecting any accessory structure, but it carves out one exception: a detached residential storage or tool shed that is accessory to a one- and two-family dwelling is exempt provided its gross floor area does not exceed 144 square feet, it does not exceed 12 feet in height, and it sits in a conforming location on the property. All three conditions must be met at once; the section does not itself spell out a specific setback distance, so a 'conforming location' still has to satisfy whatever yard and setback standards apply to accessory structures under the Town's Zoning Code (Chapter 322), which carries its own bulk schedule as a separate attachment rather than text in this chapter.

Once a shed exceeds 144 square feet, exceeds 12 feet in height, or sits in a nonconforming spot, it loses the exemption and needs a standard building permit application under § 112-10(B) through (D), including a plot plan showing its distance from lot lines. Section 112-11(1)(c) sets the flat permit fee for a shed that does require one at $115 per unit, the same flat rate charged for residential antennas, satellite dishes, fireplaces, stoves, and air-conditioning or heating units. Demolishing an accessory structure or building later carries its own $100 fee under § 112-11(3)(e).