Southampton, NY Accessory Structures: ADU Rental Restrictions (2026)

Section 330-11.1E ties the mandatory rental permit under Chapter 270, already required before any accessory apartment can be occupied, to an affordability check for apartments that received building permit approval after January 1, 2019. At permit application and again at each renewal, the owner must produce a fully executed lease or other documentation proving the rent does not exceed the annual fair market rent (FMR) that the U.S. Department of Housing and Urban Development sets for Suffolk County, and that the tenant's income meets the low-moderate or middle-income standards Chapter 216 defines by reference to the Nassau-Suffolk area median income published by HUD.

Section 330-11.2M layers additional owner-executed covenants onto existing single-family dwellings seeking this permit: only the owner-occupant may apply, and the owner must sign agreements running to the Town ensuring the principal dwelling or apartment remains the domicile of the owner-occupant with no seasonal occupancy, that the apartment remains the domicile of every tenant with no seasonal occupancy either, that the apartment cannot be sold separately from the principal residence, and that tenant income and lease documentation is produced to the Town Building Department or Director of Housing on request, with leases required to run at least one year (or a notarized affidavit in lieu of a lease where the tenant is the owner's relative). These restrictions apply on top of, not instead of, the owner-occupancy, lot-size and unit-size standards under § 330-11.2 generally.