Accessory Structures in Sussex County, DE (2026)

ADU Rules

Sussex County adopted Ordinance No. 3027 on June 25, 2024, substantially rewriting its accessory dwelling unit (ADU) rules in Chapter 115 (Zoning) and Chapter 110 (Building Code). The new rules reclassify what had been called 'garage/studio apartments' since the late 1990s as ADUs, allow them by-right (no Board of Adjustment special use exception), permit attached or detached configurations up to 1,000 square feet, allow full self-contained kitchens for the first time, and apply only in unincorporated Sussex County - not inside the incorporated towns of Rehoboth Beach, Bethany Beach, Lewes, Dewey Beach, Fenwick Island, Henlopen Acres, South Bethany, Millsboro, Milford, Seaford, Georgetown, Milton, etc., which each have their own zoning codes. One ADU per lot is permitted, only on lots of at least 10,000 square feet, and on lots smaller than 3 acres a detached ADU must be located to the rear (behind) the principal single-family dwelling.