Kent County

Permits for ADUs on parcels in unincorporated Kent County are issued by the Kent County Department of Planning Services (also known simply as the Kent County Planning Office), which is the official enforcement agency and whose Director of Planning Services is the appointed building official. Permitting is done through a combined Certificate of Use (ADU-specific under Chapter 101) and building permit (Chapter 105). The Levy Court explicitly excludes permitting work inside the limits of the 16 incorporated municipalities in Kent (Camden/Wyoming, Cheswold, Clayton, Dover, Dover AFB is a federal enclave, Felton, Frederica, Harrington, Hartly, Houston, Kenton, Magnolia, Milford, Smyrna, Viola, Woodside) — those jurisdictions operate their own ADU permit pathways.

Process overview: ADU approval in unincorporated Kent is a two-artifact process: (1) a Chapter 101 Certificate of Use application reviewed by Planning Services, and (2) a Chapter 105 building permit for the physical construction. Typical sequence: (a) owner submits ADU Certificate of Use Request form with a $50 processing fee payable to Kent County Levy Court, signed Conditions of Approval, plot plan or survey showing principal dwelling and proposed ADU footprint with setback dimensions, interior floor plan of the ADU, and — for owner-occupancy compliance — recorded notice and declaration of land-use restriction; (b) Planning Services reviews for conformance with Chapter 101 size, setback, owner-occupancy, lot-coverage, and slab requirements; (c) if the parcel is on an on-site wastewater system, owner obtains the required DNREC permit before the Certificate of Use is released; (d) owner applies for the building permit through MyGovernmentOnline with construction drawings stamped per IRC; (e) construction proceeds with the Planning Services inspection schedule; (f) final inspection and ADU certificate of occupancy. Certificate of Use is distinct from the building permit — some simple conversions of already-permitted space may require only the Certificate of Use if no new construction is involved, at the Director's discretion.

Impact fees: Kent County does not levy school, traffic, or park impact fees on residential ADUs as a matter of 2026 fee-schedule practice; the only ADU-specific fee documented in the Chapter 101 administrative pathway is the $50 Certificate of Use processing fee. The regular building permit fee for the ADU's construction scope applies per the Kent County Code Part 2 Fee Schedule and varies with valuation. Sewer connection and DNREC on-site wastewater fees apply separately if triggered. (schedule)

The Kent County Assessment Office (a division of Kent County Finance) maintains parcel-level assessment records for all real property in Kent County, including parcels within incorporated municipalities (municipalities contract to Kent County for assessment services in most cases). Kent County completed a general reassessment in 2023–2024 under a settlement-driven statewide reassessment effort and set new values effective for fiscal year 2024; as a result the county property-tax rate dropped from $0.36 per $100 of assessed value to roughly $0.0572 per $100 to achieve revenue-neutrality against the refreshed fair-market-value base. ADU additions are captured as improvements to the host parcel on the next assessment cycle; Delaware does not separately tax-parcel an attached ADU, and the state has no statewide ADU-specific assessment exemption.

Assessment policy: ADU improvements are captured either via building-permit data reported by the Department of Planning Services, via contractor filings, or via owner self-report; Kent County confirmed in its July 2024 open letter to property owners that renovations adding living space, bedrooms, or bathrooms trigger a re-appraisal to reflect the value of the addition. The Tyler Technologies mass-appraisal methodology used in the 2023–2024 reassessment applies uniformly across residential properties. Homeowners subject to the owner-occupancy declaration on a Chapter 101 ADU remain eligible for the Kent County senior and disabled property-tax-relief credits on the principal dwelling; renting the ADU does not by itself disqualify the homeowner from those credits so long as the owner resides on the property.

Kent County administers floodplain and environmental overlays that cut across its 16 incorporated municipalities and its unincorporated areas. The county's floodplain-management ordinance (Kent County Code Chapter 89) implements the FEMA National Flood Insurance Program; the effective Flood Insurance Study and FIRM panels for Kent County and incorporated areas are dated July 7, 2014 with subsequent LOMRs and pending updates along Tidbury Creek, Puncheon Run, Isaac Branch, and Iron Mine Prong. Kent contains 1,853 structures in the FEMA 100-year floodplain per the 2011 Delaware Floodplain Report (statewide figure 18,000+). Delaware does not have a CalFire-equivalent statewide WUI wildfire-hazard mapping regime, and Kent County does not operate a county-level WUI overlay.

• Kent County Floodplain Management Ordinance — Implements the FEMA National Flood Insurance Program for unincorporated Kent. ADUs proposed in a Special Flood Hazard Area (Zone A, AE) face elevation, venting, anchoring, and lowest-floor-elevation-certificate requirements that materially change construction cost. Coastal A and V zones are rare in Kent (predominantly a Delaware Bay watershed county) but present along the St. Jones River and Delaware Bay tidal reaches.
• FEMA Flood Insurance Rate Maps — Kent County and Incorporated Areas — FEMA is actively revising FIRMs along Tidbury Creek and tributaries, Puncheon Run, Isaac Branch, and Iron Mine Prong in Kent County. Owners considering ADUs on parcels near these waterways should pull the current effective panel plus any preliminary work-map-available (WMA) panels from the Delaware Flood Planning Tool at https://floodplanning.dnrec.delaware.gov/.
• DNREC Wellhead Protection and Source Water Protection Areas — DNREC administers source-water protection overlays that constrain on-site sewage design and land use within delineated wellhead protection areas. Kent County's Chapter 101 ADU ordinance expressly prohibits creation of an ADU served by an on-site wastewater system without a prior DNREC permit, which captures the overlay's operational effect without requiring a separate county overlay ordinance.
• Delaware Coastal Zone Act jurisdiction — Delaware's Coastal Zone Act primarily restricts heavy industrial and manufacturing uses within the coastal strip; it does not substantively regulate single-family residential or ADU development, but owners near the Bay or coastal wetlands should confirm wetlands-delineation compliance via DNREC before siting a detached ADU.
• Historic Districts (local) — Kent County does not operate a county-wide historic-preservation overlay for unincorporated parcels; historic-district review operates at the municipal level inside incorporated cities. Owners in or adjacent to a locally listed historic district should check with the relevant municipal historic-preservation commission before siting an ADU.