Frankford

Sussex County adopted Ordinance No. 3027 on 2024-06-25, overhauling its accessory dwelling unit rules and reclassifying what had been labeled 'garage/studio apartments' in the 1990s code as ADUs. The ordinance amended Chapter 110 (Subdivisions), Article III, Section 110-9, and Chapter 115 (Zoning) Articles I, IV, V, VI, VII, VIII, IX, and XXVII at Sections 115-4, 115-20, 115-23, 115-29, 115-32, 115-40, 115-48, 115-53, 115-56, 115-64, and 115-210. The definition-level change is in Chapter 115 Article I; the use-table entries are in each residential district's article; and the supplementary regulations (size, setback, parking, etc.) live in Article XXV (Supplementary Regulations). Key policy changes: ADUs now allowed by right in most residential districts without a Board of Adjustment special-use exception; maximum ADU floor area increased from 800 to 1,000 sq ft; self-contained kitchens now permitted (previously prohibited); both attached and detached ADUs allowed; minimum lot size 10,000 sq ft; ADU cannot be placed in front of the primary residence on lots under 3 acres; existing front/side/rear setbacks for the underlying district apply; one off-street parking space required; total lot coverage capped at 50%; may be owner-occupied or rented. The ordinance applies only in unincorporated Sussex County — incorporated municipalities (Rehoboth Beach, Lewes, Bethany Beach, Milton, Seaford, Milford, Georgetown, Laurel, Bridgeville, Millsboro, Selbyville, Dagsboro, Delmar, Frankford, Greenwood, Ellendale, Bethel, Harbeson unincorporated, Lincoln unincorporated) handle their own ADU rules. Private deed restrictions and HOA covenants take precedence over the county ordinance.

• Sussex County Code Chapter 115 Article XXV — Supplementary Regulations
• Sussex County Code Chapter 115 Article I — General Provisions (definitions)
• Sussex County Code Chapter 115 Article IV — AR-1 and AR-2 Agricultural Residential Districts
• Sussex County Code Chapter 115 Article V — MR Medium-Density Residential District
• Sussex County Code Chapter 115 Article VI — GR General Residential District
• Sussex County Code Chapter 115 Articles VII, VIII, IX — HR-1, HR-2 High-Density and UR Urban Residential Districts
• Sussex County Ordinance 3027 listing page
• Sussex County news release on ADU ordinance adoption

State-floor overlay: Delaware has NOT enacted a statewide ADU preemption law; the only state pressure on Sussex County's ADU rules is the non-binding technical-assistance provided through DSHA's Zoning and Land Use Reform Pilot Program (Senate Joint Resolution 8, 2024), of which Sussex County is a participant. Neither SB 23 (152nd General Assembly) nor SB 87 (153rd General Assembly, tabled at Senate floor) has passed, so Sussex County's Ordinance 3027 operates without a state preemption floor and represents the controlling law for unincorporated parcels.

Sussex County administers a Flood-Prone Districts overlay (Chapter 115 Article XVIII) that implements FEMA NFIP standards countywide; roughly 20% of Sussex parcels sit within a mapped Special Flood Hazard Area (SFHA), heavily concentrated along the Atlantic coast (Rehoboth, Dewey, Bethany, South Bethany, Fenwick Island), Delaware Bay (Broadkill, Slaughter Beach), and the Inland Bays (Rehoboth Bay, Indian River Bay, Little Assawoman Bay). Atop the county overlay, Delaware DNREC administers the state Coastal Zone Act regulated area and the Delaware Coastal Management Program (NOAA-approved CZMA program since 1979) — the CZA regulated area covers Sussex's entire Atlantic-coast and bay-shore band and governs major industrial land uses more than ADUs, but ADUs within the CZMA-mapped area still encounter DNREC review where a state subaqueous lands or wetlands permit is triggered. The Delaware Bay and Atlantic Ocean coastal band also sits within NFIP VE zones (velocity/wave action) where ADU construction requires elevation and breakaway-wall detailing. The county does NOT administer a wildland-urban interface (WUI) overlay — Delaware is not a WUI state. Historic-district overlays are handled by individual municipalities (Lewes, Rehoboth Beach, Milton, Milford, Seaford) rather than at the county level.

• Sussex County Flood-Prone Districts Overlay — Sussex County's local implementation of FEMA NFIP floodplain-management standards. FIRMs most recently updated and affirmed by FEMA 2015-03; Round Pole Branch and Clear Brook studies ongoing. An ADU within a mapped SFHA (Zone A, AE, or VE) faces elevation, venting, anchoring, and — in V zones — breakaway-wall requirements that materially change construction cost. Lowest-finished-floor must meet or exceed the base flood elevation plus any adopted freeboard.
• Sussex County Flood Map Ordinance administrative page — Administrative landing page linking the county ordinance text, the FIRM viewer, and the parcel-lookup workflow for confirming SFHA status before submitting a permit application.
• Delaware Coastal Zone Act / CZMA regulated area — The Delaware CZA regulated area spans the entire Atlantic coast of Sussex County and the Delaware Bay and Inland Bays shoreline. CZA review focuses on heavy industry and port uses — ADUs are not themselves a CZA-triggering use — but the broader CZMA consistency review applies to federally permitted actions and to state subaqueous-lands/wetlands permits that a shore-proximate ADU might trigger.
• DNREC Wetlands and Subaqueous Lands jurisdiction — State-level overlay that can affect ADU siting on tidal-wetland-adjacent parcels and on parcels extending into subaqueous lands. DNREC review is separate from county zoning review and can add 60-180 days to the permitting clock for shore-proximate parcels.
• DNREC Floodplain Management — State floodplain-management program that coordinates with Sussex County's local ordinance. DNREC maintains the Delaware Flood Planning Tool (https://floodplanning.dnrec.delaware.gov/) for parcel-level SFHA and sea-level-rise scenario lookup, which is a useful pre-application screen for ADU proposals on Sussex coastal parcels.
• FEMA National Flood Insurance Program (NFIP) participation — Sussex County is an NFIP-participating community; ADUs on parcels in V zones require engineered foundations and cannot have enclosed habitable space below base flood elevation. ADUs in A/AE zones must have elevated finished floors and flood-vented crawlspaces. Community Rating System (CRS) discounts for flood-insurance policyholders depend on the community's CRS class, which is reviewed on a 5-year cycle.

Permits for ADUs on parcels in unincorporated Sussex County are issued by the Sussex County Planning & Zoning Office (zoning compliance) and the Sussex County Building Code Department (building permit). Under Ordinance 3027 (2024), ADUs are a by-right use in the Agricultural Residential (AR-1, AR-2), Medium-Density Residential (MR), General Residential (GR), High-Density Residential (HR-1, HR-2), and Urban Residential (UR) districts provided the parcel meets the 10,000 sq ft minimum, 50% lot-coverage cap, and the ADU does not sit in front of the primary residence on parcels under 3 acres. No Board of Adjustment special-use exception is required for an ADU that conforms to Article XXV; a non-conforming proposal still needs a variance. Incorporated municipalities inside Sussex (Rehoboth Beach, Lewes, Bethany Beach, Milton, Seaford, Milford, Georgetown, Laurel, Bridgeville, Millsboro, Selbyville, Dagsboro, Delmar, Frankford, Greenwood, Ellendale, Bethel) handle their own ADU permits through their own code-enforcement offices and are NOT covered by this unincorporated-permitting record.