Bolthole Index

New Castle County, Delaware

Building permits, zoning and land rules in New Castle County, Delaware

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Unincorporated New Castle County, Delaware requires a building permit for a home or other structure, followed by county inspections and a Certificate of Occupancy123. County zoning and subdivision rules also apply to unincorporated land45. Wilmington, Newark, Delaware City and Townsend run their own zoning6789. Delaware DNREC, not the county or a town, permits septic systems and wells1011.

At a glance

Building permit
Required — issued by the Department of Land Use12
Zoning
Yes — countywide Unified Development Code13
Septic (OSSF) permit
Permitted by the state (DNREC), not the county14
Owner-builder exemption
Conditional — owner-occupiers must meet county requirements15
Tiny home / ADU
Allowed as an accessory dwelling unit, one per lot16
Manufactured home
Limited — only in a manufactured home park or on ag-zoned land17
New single-family building permit fee
$12 per $1,000 of valuation, plus a $60 C.O. fee18
Private well
DNREC permit and licensed well contractor required11
Minimum home size
No countywide minimum confirmed; 800 sq ft per apartment when converting an old house to apartments19

Who to call

Building permits

New Castle County Department of Land Use

Building permits, zoning, code enforcement and land-use administration for unincorporated New Castle County

302-395-5400

87 Reads Way, New Castle, DE 19720

Online permits →

Septic permits

DNREC Division of Water

Statewide septic (onsite wastewater) and well permitting for New Castle County and the rest of Delaware

302-739-9947

Richardson and Robbins Building, 89 Kings Highway, Dover, DE 19901

Contact details are copied from each office’s official page and were checked against it on October 16, 2026.

Off-grid gear

Going off-grid in New Castle County means bringing your own water and power. The kit we’d start with:

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Do you need a building permit in New Castle County, DE?

Unincorporated New Castle County requires a building permit for new buildings, alterations and most repairs, issued and enforced by the Department of Land Use under County Code Chapter 6121. Work is exempt only if the county's exempt-work list names it; if a project is not on that list, assume a permit is required1. The county has adopted the 2024 building, residential, existing-building, and swimming-pool codes; the 2018 energy code; and the 2021 mechanical, fuel-gas, and plumbing codes20. After permit issuance, the county inspects applicable stages of work, and construction cannot pass an inspection point without approval2. A final inspection and Certificate of Occupancy or Use are required before a permitted building can be occupied3. For a new single-family home, the building permit costs $12 per $1,000 of valuation and the occupancy certificate costs $6018. An owner-occupier may act as their own new-home builder only under a one-time exemption approved by the Code Official; the owner cannot put an unlicensed person in charge and remains responsible for compliance15.

Who is the New Castle County building department, and how do you reach them?

The New Castle County Department of Land Use is the county's building department, handling permits, planning and zoning from the New Castle County Government Center, 87 Reads Way, New Castle, DE 1972021. Planning & Permits can be reached at 302-395-5400, and Code Enforcement at 302-395-555521. The office is open Monday through Friday, 8 a.m. to 4 p.m.21. Applications and plans for construction in unincorporated areas can be submitted electronically, and typical documentation includes lines-and-grades, drainage, erosion-control, sewage-disposal, building, mechanical and plumbing documents22. If your land sits inside an incorporated town rather than unincorporated New Castle County, that municipality issues its own permits instead23. Septic and well permits still come from DNREC at every address, town or not10.

Does New Castle County have zoning?

New Castle County zones unincorporated land under its Unified Development Code, which controls zoning districts and the use, bulk, design, and location of land and buildings4. The same code regulates land subdivision, so splitting or developing a tract may require Department of Land Use review and other approvals5. Lot standards are district-specific: for example, the NC10 residential district requires at least 10,000 square feet24. Commercial-stable rules are also specific: SR and SE parcels need at least 5 acres and 300 feet of width, while S parcels need at least 3 acres and 200 feet; their street, side, rear, and height limits differ252627282930. Inside Wilmington, Newark, Delaware City and Townsend, the town's own zoning code applies instead of the county's6789. The county sets no single minimum house size for new homes that we could confirm; the one fixed floor-area figure in its code applies to converting an old single-family house into apartments, where each apartment must be at least 800 square feet19. Confirm the parcel's district before planning a home, stable, RV use, tiny home, or lot split31.

How do septic permits work in New Castle County?

Septic systems in New Castle County are a state matter: Delaware DNREC administers the onsite-wastewater approval process10. Before applying for a new or replacement system permit, a Class D soil scientist must prepare the site evaluation; a licensed Class B designer handles a gravity system, while a Class C designer handles an engineered or pressure-dosed system; installation requires a Class E contractor32. Only about 12.4% of New Castle County soils lack severe limitations for a conventional drain field, so determine septic feasibility before relying on an undeveloped parcel33. Installations and repairs are inspected unless DNREC waives a qualifying pre-cover inspection, and a sale generally requires pumping and inspection unless an exception applies34. Off-grid does not mean untreated: wastewater fixtures must connect to a central system or a DNREC-approved onsite system, though DNREC may approve alternative technology that provides equivalent treatment35. DNREC's Division of Water answers septic questions at 302-739-9947 and well-permit questions at 302-739-994436.

Can you live in an RV or tiny home on your land in New Castle County?

New Castle County treats a tiny home as an accessory dwelling unit, not as a way around zoning: it can be added to a qualifying single-family lot if it meets County Code's ADU standards, only one ADU is allowed per lot, and the owner must live in either the main house or the ADU as their primary residence16. A detached tiny home or ADU needs at least half an acre of lot, plus its own building permit and Certificate of Occupancy, before anyone can live in it37. Delaware's housing code uses an occupant-based floor-area standard rather than one fixed minimum home size: at least 150 square feet for the first occupant and 100 square feet for each additional occupant38. Manufactured or modular housing that does not qualify as a single-family dwelling is limited to a manufactured home park or agricultural-zoned land and requires a state-licensed installer and county use permit17. We could not confirm the current rule for residential RV occupancy or ordinary temporary camping on private land; ask the Department of Land Use before relying on either use21.

Building a home in New Castle County: the steps, in order

  1. Confirm zoning and whether subdivision review applies. Use the county's maps or request a zoning certification, and ask the Department of Land Use before splitting or developing a tract31521.
  2. Resolve wastewater and water. Obtain the soil evaluation and licensed septic design needed for a DNREC permit; if using a well, have a licensed well contractor submit the DNREC application3211.
  3. Submit the county application and plans. Electronic filing is available, and typical documents cover lines and grades, drainage, erosion control, sewage disposal, building, mechanical, and plumbing work22.
  4. Budget for approvals. A new single-family permit costs $12 per $1,000 of valuation, plus a $60 occupancy-certificate fee and a zoning fee equal to 10% of the building-permit fee, subject to a $21 minimum and $145 maximum18.
  5. Clear access and floodplain issues. A new or modified driveway may require a DelDOT entrance permit, while regulated flood-hazard development must meet county floodplain rules3940.
  6. Schedule each required county inspection and do not build past an inspection point without approval2. After the final inspection and correction of outstanding issues, obtain the Certificate of Occupancy or Use before moving in3.

What to check before you buy land in New Castle County

New Castle County has about 1,357 people per square mile, and the nearest city of 100,000 or more is about 42 miles from the county center4142. Only about 12.4% of county soils lack severe limitations for a conventional septic drain field, so establish septic feasibility before buying outside a sewer service area33. If the parcel needs a well, budget for a DNREC permit, a licensed well contractor, and contamination review of the proposed location11. For sewer, contact the county's drafting department to learn whether a connection is feasible; the county does not own or maintain water lines, so ask the local water company about water service43. Check flood maps because regulated flood-hazard development must comply with county floodplain rules40. Confirm legal driveway access because a new or modified driveway may require a DelDOT entrance permit39. Typical property taxes are about 0.7% of value, with a median annual bill near $2,4444445.

Watch-outs

  • New Castle County's Unified Development Code sets parcel-specific lot, setback and height limits; NC10's 10,000-square-foot minimum, for example, does not establish the minimum for every district24.
  • Inside Wilmington, Newark, Delaware City and Townsend, the town sets its own zoning instead of the county; confirm each town's building-permit office before you apply6789.

Sources

  1. Figure Out What Permits You Need, quoted and re-checked
  2. New Castle County Chapter 6 Building Code, quoted and re-checked
  3. New Castle County Chapter 6 Building Code, quoted and re-checked
  4. Zoning | New Castle County, DE, quoted and re-checked
  5. newcastlede.gov, quoted and re-checked
  6. Wilmington: Wilmington Code Sec. 48-138 R-5-B districts (New Castle County), quoted and re-checked
  7. Newark: Newark Code Sec. 32-10 RD districts (New Castle County), quoted and re-checked
  8. Delaware City: Delaware City Code Sec. 46-3 Definitions (New Castle County), quoted and re-checked
  9. Town of Townsend: Ordinance 13-03 Comprehensive Rezoning (adopted 2013-09-04) (New Castle County), quoted and re-checked
  10. Septic Systems, quoted and re-checked
  11. Well Permits, quoted and re-checked
  12. Figure Out What Permits You Need (2026 county census)
  13. Zoning | New Castle County, DE (2026 county census)
  14. Delaware DNREC Septic Systems (2026 county census)
  15. New Castle County Chapter 6 Building Code, quoted and re-checked
  16. newcastlede.gov, quoted and re-checked
  17. Manufactured Modular Home Permit Requirements, quoted and re-checked
  18. Single Family Dwelling Building Permit Requirements, quoted and re-checked
  19. Chapter 40, Article 3 - Use Regulations, quoted and re-checked
  20. County Laws & Code | New Castle County, DE, quoted and re-checked
  21. New Castle County Department of Land Use (newcastlede.gov)
  22. Online Payments - Land Use, quoted and re-checked
  23. Zoning | New Castle County, DE, quoted and re-checked
  24. Zoning | New Castle County, DE, quoted and re-checked
  25. Land Use - Residential Use Frequently Asked Questions, quoted and re-checked
  26. Land Use - Residential Use Frequently Asked Questions, quoted and re-checked
  27. Land Use - Residential Use Frequently Asked Questions, quoted and re-checked
  28. Land Use - Residential Use Frequently Asked Questions, quoted and re-checked
  29. Land Use - Residential Use Frequently Asked Questions, quoted and re-checked
  30. Land Use - Residential Use Frequently Asked Questions, quoted and re-checked
  31. Zoning, quoted and re-checked
  32. Septic Systems, quoted and re-checked
  33. Share of soils USDA rates "not limited" for a conventional septic drain field (SSURGO). A strict rating: the median county is about 6% and a tenth of counties are 0%, so a low figure means most lots need a site evaluation or an engineered system, not that septic is impossible. Cite it only with that caveat: Bolthole Index county data
  34. 7101 Regulations Governing the Design, Installation and Operation of On-Site Wastewater Treatment and Disposal Systems, quoted and re-checked
  35. Septic Systems, quoted and re-checked
  36. DNREC Division of Water (dnrec.delaware.gov)
  37. Accessory Dwelling Unit Requirements, quoted and re-checked
  38. Delaware State Housing Code, Title 31, Chapter 41, Subchapter II (Delaware statewide rule), quoted and re-checked
  39. newcastlede.gov, quoted and re-checked
  40. Article 10 Floodplain Management Regulations, quoted and re-checked
  41. Population density: Bolthole Index county data
  42. Straight-line distance from the county center to the nearest city of 100,000+ people: Bolthole Index county data
  43. New Castle County Frequently Asked Questions — Public Works, quoted and re-checked
  44. Effective property tax rate: Bolthole Index county data
  45. Median property tax bill: Bolthole Index county data

Written October 16, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.

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Compared with neighboring counties

RuleNew Castle CountyKent CountySussex County
Building permitRequiredRequiredRequired
County zoningYesYesYes
Septic permitsDE DNRECDE DNRECDE DNREC

County locator

New Castle County in Delaware

46
County map
New Castle County highlighted among the Delaware counties · colored by Index score

How New Castle County scores

Seclusion16100% ev.
Self-Sufficiency68100% ev.
Admin Boringness44100% ev.
Durability77100% ev.
Property Autonomy53100% ev.
Carry Cost57100% ev.

Evidence strength: 100%. This reports direct-source completeness and fallback use; it is separate from the score and is not a confidence interval. How it works →

$375kTypical home
0.7%Property tax
$11,212Land / acre
46.1"Annual rain
1.4% of yrsSevere drought
3.7 / yr (+3.5)Mid-century 100°F days
12.9 daysMid-century dry spell
2.48" (+8.9%)Mid-century 1-day rain
1.45×Wildfire change factor
100%Forward climate coverage
$1,188Home insurance / yr
2.3% / yrInsurance growth
0.83%Nonrenewal rate
county median (2+ published ZIPs)Insurance basis
236,344People within 30 min
14,997,054People within 2 hr
563,631Radius comparison (15 mi)
1,357.1People / sq mi
1.3%Federal land
95.7%Land at 15% slope or less
12.4%Soils rated "not limited" for septic (strict USDA rating)
25,544 acWorkable land screen
83.9 tonsBiomass / forest ac
55.2°FAvg temp

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Cities and towns in New Castle County

Inside a city or town, that city usually issues building permits and sets zoning; the county’s rules above cover unincorporated land. Septic, wells and floodplain rules usually stay with the county or state everywhere.

Not yet researched: Village of Arden · Village of Ardencroft · Village of Ardentown · Town of Bellefonte · Town of Middletown · Town of Newport · Town of Odessa · Town of Townsend

Answers from the rulebook for New Castle County

What the ordinances and state agencies actually say — one answer per question, each quoted from the official source and independently re-checked.

New Castle County rules

  • Building permitRequired

    Construction activity, including new buildings and single-family dwelling construction, in unincorporated New Castle County.

    • A permit is required unless the work is specifically exempted by New Castle County Code Chapter Six, Section 06.03.012.
    • The county's page states that if a project does not appear on the county's Work Exempt from Permit list, the applicant should assume a permit is required.
    • New Castle County identifies single-family dwelling construction as a permit type.
    • Incorporated municipalities may administer their own permitting rules.
    “All construction activity including new buildings, interior and exterior improvements, alterations, and most repairs requires a permit unless the work is specifically exempted by the New Castle County Code, Chapter Six, Section 06.03.012 (Permits).”
  • Owner-builder exemptionConditional

    Owner-occupiers acting as their own contractor for residential accessory structures, additions, renovations, plumbing work, or as their own new-home builder for a single-family dwelling in unincorporated New Castle County.

    • For residential accessory structures, additions, and renovations, the owner/occupier must own and occupy the dwelling, the property must not be for sale or partly for rent, and the owner must act as the building contractor or intend to complete all work covered by the permit.
    • A homeowner may install plumbing in the owner's private dwelling by obtaining a homeowner's plumbing permit without being licensed as a contractor.
    • The single-family dwelling exemption is one-time and requires Code Official approval and a certification that the owner/occupier will act as their own new-home builder until completion.
    • The Code Official may revoke the exemption if the owner/occupier is not completely acting as their own new-home builder.
    • Further exemption applications after the one-time exemption may be approved at the Code Official's discretion.
    • The owner-occupier may not hire an unlicensed person to act as contractor or supervise subcontractors and remains responsible for code violations and compliance with applicable laws, building codes, and zoning regulations.

    single-family new-home-builder exemption frequency: one-time (Further applications may be approved at the Code Official's discretion.)

    “the code provides a one-time exemption enabling an owner-occupier to function as their own new home builder”
  • Building code adoptedAdopted (with conditions)

    County-administered construction in unincorporated New Castle County.

    • The Department of Land Use administers and enforces the New Castle County Building Code.
    • The adopted standards include the 2024 International Building Code, 2024 International Residential Code, 2024 International Existing Building Code, 2024 International Swimming Pool and Spa Code, 2018 International Energy Conservation Code, 2021 International Mechanical Code, 2021 International Fuel Gas Code, and 2021 International Plumbing Code.
    • The county states that Chapter 6 and its appendices contain amendments to the adopted codes.
    • The listed effective dates are January 1, 2026 for the 2024 building, residential, existing building, and swimming pool codes; January 1, 2021 for the 2018 energy code; and January 1, 2024 for the 2021 mechanical, fuel gas, and plumbing codes.

    International Building Code edition: 2024 · International Residential Code edition: 2024 · International Existing Building Code edition: 2024 · International Swimming Pool and Spa Code edition: 2024 · International Energy Conservation Code edition: 2018 · International Mechanical Code edition: 2021 · International Fuel Gas Code edition: 2021 · International Plumbing Code edition: 2021

    “The Department of Land Use regulates construction to the standards of the Codes listed below. To access these Codes at no charge, please visit this ICC webpage.”
  • InspectionsRequired

    Construction and work performed under a New Castle County building permit in unincorporated New Castle County.

    • After a building permit is issued, the Code Official must conduct inspections during and upon completion of the permitted work.
    • Special inspections may be required; the permit holder is responsible for their cost.
    • Required inspection phases include footing and foundation, exterior framing, weather barrier, close-in, insulation, and final inspection, as applicable.
    • Final inspection is required after completion and before occupancy.
    • The permit holder or authorized agent must notify the Code Official when work is ready and provide access; work may not proceed beyond each inspection point without approval.
    • County employees perform required inspections unless an approved inspection agency or Delaware-licensed design professional is approved to perform them.
    “After issuing a building permit, the Code Official shall conduct inspections from time to time during and upon completion of the work”
  • Certificate of occupancyRequired

    Use or occupancy of buildings and structures, and changes in existing use or occupancy classification, in unincorporated New Castle County.

    • No building or structure may be used or occupied, in whole or in part, and no change in occupancy classification may occur until the Code Official issues a certificate of occupancy or use.
    • Certificates are not required for work exempt from permits under Section 06.03.012.
    • A certificate for a tenant or lease space in a new or renovated building requires a determination that the building is complete according to approved construction documents.
    • A change in use or occupancy must also comply with Chapter 40.
    • The certificate is issued after final inspection, correction of outstanding violations and discrepancies, correction of approved plans or permit issues, and satisfaction of Code Official directives.
    • Temporary certificates may be issued for safe portions for 30 days, renewable for successive 30-day periods at the Code Official's discretion, with the applicable fee paid before issuance or renewal.

    temporary certificate period: 30 days (May be renewed for successive 30-day periods at the Code Official's discretion.)

    “Before the new or improved building can be inhabited, a Certificate of Occupancy must be secured from the Department.”
  • County-wide zoningPresent (with conditions)

    Zoning and land-use regulation administered by New Castle County in unincorporated areas.

    • The Unified Development Code regulates creation and administration of zoning districts and the use, bulk, design, and location of land and buildings.
    • A zoning certification identifies the applicable zoning district and whether a proposed use is permitted or not permitted.
    • Projects may require additional permits, plans, reviews, or outside-agency approvals.
    “The UDC also regulates and controls the following: creation and administration of zoning districts; general development of real estate in the unincorporated areas of New Castle County; planning and subdivision of lands; and use, bulk, design and location of land and buildings.”
  • Local zoningVaries (with conditions)

    Aggregate zoning and related local land-use regulation across New Castle County, including county-administered unincorporated areas and incorporated municipalities.

    • New Castle County administers zoning and subdivision regulations in the county's unincorporated areas.
    • Incorporated municipalities have their own local codes and may administer their own local permitting and land-use requirements.
    • The county identifies local municipality codes separately and advises applicants to consult applicable local codes.
    “Each county or municipality sets its own permitting and floodplain regulations. Always refer to local codes before proceeding.”
  • Zoning districtsPublished (with conditions)

    Zoning districts and zoning-map administration in unincorporated New Castle County.

    • The UDC regulates creation and administration of zoning districts and development in unincorporated areas.
    • The county page identifies urban, suburban-transition, suburban, and special districts, including TN, ST, MM, ON, OR, CR, BP, I, CN, S, SE, SR, NC, HI, EX, H, and HT.
    • Applicable zoning must be confirmed for the specific parcel using county zoning maps or a zoning certification.
    • Incorporated municipalities may have separate zoning codes and districts.
    “The UDC also regulates and controls the following: creation and administration of zoning districts; general development of real estate in the unincorporated areas of New Castle County”
  • Minimum dwelling sizeSpecified

    Apartments or residential condominium units created through a multifamily conversion under New Castle County Unified Development Code Section 40.03.340.

    • The multifamily conversion is not permitted on a parcel within one thousand (1,000) feet of a heavy-industry-zoned parcel or a parcel with a heavy-industry use.
    • Legally existing commercial or office gross floor area may be converted subject to Section 40.31.711, excluding mixed-use developments.
    • A land-development application proposing new gross floor area is reviewed under the underlying district's standards and the applicable resubdivision, minor-plan, or major-plan process.
    • The conversion may yield one dwelling unit for every eight hundred (800) square feet of gross floor area.
    • The average size of an apartment or residential condominium unit must be at least eight hundred (800) square feet of gross floor area.
    • At least two hundred (200) square feet of yard, balcony, deck, or rooftop area must be provided for each unit.
    • Moderately priced dwelling units are required under Article 7.

    minimum average unit size: >= 800 square feet of gross floor area · unit yield: per 800 square feet of gross floor area per dwelling unit · minimum outdoor area per unit: >= 200 square feet

    “Multifamily conversion may yield one dwelling unit for every eight hundred (800) square feet of GFA. The average size of an apartment or residential condominium unit in a multifamily conversion must be at least eight hundred (800) square feet of GFA.”
    One more reviewed finding on this topic
    • Specified — Each apartment created through conversion of a single-family detached dwelling into two or more dwelling units under New Castle County Unified Development Code Section 40.03.304.
      “The minimum floor area of each apartment shall be eight hundred (800) square feet.”
  • Minimum lot sizeDistrict specific (with conditions)

    Residential Neighborhood Conservation NC10 zoning district in the unincorporated areas of New Castle County.

    • The UDC applies to general development in the unincorporated areas of New Castle County.
    • The county page describes NC10 as a Neighborhood Conservation district with a minimum 10,000 square foot lot size.

    minimum lot size: >= 10000 square feet

    “NC (Neighborhood Conservation) - residential, existing developments, numbers following denote lot size or type of residential development (e.g., NC10 indicates Neighborhood Conservation with minimum 10,000 square foot lot size; NCAP indicates Neighborhood Conservation with apartments”
  • SetbacksDistrict specific (with conditions)

    Commercial stables in the Suburban Reserve (SR) zoning district.

    • Commercial stables are subject to limitations.
    • The stable must not conflict with the low-density nature of the zoning district.
    • A site plan must be submitted to the Department of Land Use for approval.
    • A maximum of 25% of the site may be improved with barns, stables, riding rinks, parking or other facilities.
    • One parking space is required for every two stalls.
    • The SR parcel must be at least 5 acres and at least 300 feet wide.
    • Stables cannot be located in the floodplain, floodway, wetlands, riparian buffers, drainageways, wellhead/water recharge areas or on steep slopes.

    minimum parcel area: >= 5 acres · minimum parcel width: >= 300 feet · street setback: >= 100 feet · side-yard setback: >= 50 feet · rear-yard setback: >= 100 feet

    “In the SR zoning district, the parcel must be at least 5 acres. The parcel must be at least 300 ft wide. The setback from the street must be at least 100 feet, from the side yard at least 50 feet and from the rear yard at least 100 feet.”
    2 more reviewed findings on this topic
    • District specific (with conditions) — Commercial stables in the Suburban Estate (SE) zoning district.
      “In the SE zoning district, the parcel must be at least 5 acres. The parcel must be at least 300 ft wide. The setback from the street must be at least 100 feet, from the side yard at least 30 feet and from the rear yard at least 100 feet.”
    • District specific (with conditions) — Commercial stables in the Suburban (S) zoning district.
      “In the S zoning district, the parcel must be at least 3 acres. The parcel must be at least 200 ft wide. The setback from the street must be at least 50 feet, from the side yard at least 40 feet and from the rear yard at least 50 feet.”
  • Building heightDistrict specific (with conditions)

    Commercial stables in the Suburban (S) zoning district.

    • Commercial stables are subject to limitations.
    • A site plan must be submitted to the Department of Land Use for approval.
    • The S parcel must be at least 3 acres and at least 200 feet wide.
    • The building-height limit applies to the commercial stable building.

    maximum building height: <= 40 feet

    “In the S zoning district, the parcel must be at least 3 acres. The parcel must be at least 200 ft wide. The setback from the street must be at least 50 feet, from the side yard at least 40 feet and from the rear yard at least 50 feet. The building may be no taller than 40 feet.”
    2 more reviewed findings on this topic
    • District specific (with conditions) — Commercial stables in the Suburban Reserve (SR) zoning district.
      “In the SR zoning district, the parcel must be at least 5 acres. The parcel must be at least 300 ft wide. The setback from the street must be at least 100 feet, from the side yard at least 50 feet and from the rear yard at least 100 feet. The building may be no taller than 50 feet.”
    • District specific (with conditions) — Commercial stables in the Suburban Estate (SE) zoning district.
      “In the SE zoning district, the parcel must be at least 5 acres. The parcel must be at least 300 ft wide. The setback from the street must be at least 100 feet, from the side yard at least 30 feet and from the rear yard at least 100 feet. The building may be no taller than 40 feet.”
  • Tiny homesAllowed (with conditions)

    Small single-family homes, including tiny homes, used as accessory dwelling units on qualifying single-family detached residential lots in unincorporated New Castle County.

    • The tiny home must qualify as an accessory dwelling unit under County Code Chapter 40, Section 03.410(I).
    • Only one ADU is permitted per single-family residential detached lot.
    • The property owner must occupy and reside in either the principal dwelling or the ADU as the principal legal residence.
    • An ADU building permit must be issued and a Certificate of Occupancy granted.
    • A detached ADU may be constructed or used in a freestanding accessory structure on a lot of at least one-half acre, subject to the principal dwelling's front, street, side, and rear setbacks.
    • One additional off-street parking space is required.
    • Only one of the two dwelling units may be rented, and any rental must be registered before issuance of the Certificate of Occupancy.

    detached ADU minimum lot size: >= 0.5 acre (Attached ADUs are not subject to this detached-structure threshold in the cited permit sheet)

    “Permit Small Single-Family homes (e.g., tiny homes) as ADUs”
  • Manufactured homesLimited

    Manufactured or modular housing not defined as a single-family dwelling under Chapter 40 in unincorporated New Castle County.

    • Such housing may be installed only within a manufactured home park or for agricultural-zoned housing.
    • A County use permit application is required.
    • A State of Delaware manufactured-home installer license is required, and a licensed installer must oversee all installation aspects.
    • Building plans, a current plot plan or survey, and a manufacturer's installation manual certifying HUD standards are required as applicable.
    • For new lot placements, sewer agreement, DNREC septic approval, and DNREC well approval may be required.
    • Installation permit fee is $200 for a single-section manufactured home and $300 for a double-section manufactured home.
    • All new dwellings may be subject to service-related impact fees.

    single-section installation permit fee: 200 USD · double-section installation permit fee: 300 USD

    “The installation of manufactured or modular housing not defined as an SFD may only be installed within a manufactured home park or for agricultural-zoned housing.”
  • Accessory dwellingsAllowed (with conditions)

    Accessory dwelling units added to or created within a single-family detached dwelling in unincorporated New Castle County.

    • An ADU building permit must be issued and a Certificate of Occupancy granted.
    • Only one ADU is permitted per single-family residential detached lot.
    • The property owner must occupy and reside in either the principal dwelling unit or the ADU as the principal legal residence.
    • Only one of the dwelling units may be rented, and any rental must be registered before issuance of the Certificate of Occupancy.
    • One additional off-street parking space is required.
    • A detached ADU may be located in a freestanding accessory structure on a lot of at least one-half acre, subject to the principal dwelling's setbacks.
    • The unit must conform to New Castle County Code Chapters 6 and 12 at permit issuance.

    detached ADU minimum lot size: >= 0.5 acre (Attached ADUs are governed by the attached-ADU requirements)

    “Only one ADU is permitted per single-family residential detached lot.”
  • Mandatory utility hookupConditional

    Sanitary-sewer and water-line connections for properties in New Castle County; availability and feasibility are location-specific.

    • Sewer availability and connection fees vary by location and proposed use.
    • A property must contact the County drafting department to determine connection feasibility.
    • New Castle County does not own or maintain water lines; local water companies must be contacted for water service.
    • County rules require lots discharging sanitary sewage to be permanently connected to a compliant wastewater disposal system.

    lateral connection fee: 101 USD · document recordation fee: 64-170 USD · single-family detached design flow: 300 GPD

    “Applicable connection fees and sewer availability vary by location and proposed use.”
  • Subdividing landRegulated (with conditions)

    Subdivision and land development in unincorporated New Castle County

    • A major or minor land development plan is required if a project will subdivide land or add more than 1,000 square feet of gross floor area.
    • The plan is reviewed under the Unified Development Code and may require public hearings and additional applications, plans, studies, or permits.
    • Outside agencies may impose additional requirements.

    gross floor area threshold: > 1000 square feet (The County page states that subdividing land or adding more than 1,000 square feet requires a major or minor land development plan.)

    “If your project will subdivide land or add more than 1,000 square feet of gross floor area, you must submit a major or minor land development plan.”
  • Driveway accessLimited

    Existing driveway expansions and new or modified driveways in New Castle County.

    • Expansion or enlargement of an existing driveway does not require a New Castle County building permit.
    • Driveway expansions must comply with the Unified Development Code.
    • Any new or modified driveway may require an entrance permit from DelDOT.
    • An uncovered driveway, except for a shared driveway, may project into any yard if it is set back at least two feet from any lot line.

    minimum driveway setback from lot line: >= 2 feet (shared driveways are excluded from the quoted projection rule)

    “Any new or modified driveway may require an entrance permit from DelDOT.”
  • Building in a floodplainRequired

    Development, new construction, and substantial improvements in New Castle County special flood hazard areas and other areas regulated under Article 10.

    • All development and new construction must comply with the floodplain-management regulations in effect at the time of construction.
    • Development, new construction, and substantial improvements must also comply, as applicable, with flood-load and flood-resistant construction provisions of the building code.
    • The ordinance became effective February 4, 2015.
    • Current or amended FEMA flood maps and studies establish special flood hazard areas; certain nondelineated floodplains may require an applicant-submitted flood study by a professional engineer.

    ordinance effective date: 2015-02-04

    “all development and new construction as defined herein, are to be compliant with New Castle County’s floodplain management regulations”
  • Permit feesPublished (with conditions)

    New single-family dwelling building permits in unincorporated New Castle County.

    • Building permit fee is $12 per $1,000 of valuation.
    • Certificate of Occupancy fee is $60.
    • Zoning permit fee is 10% of the building permit fee, with a $21 minimum and $145 maximum.
    • The Volunteer Fire Assistance Fund fee is 0.5% of valuation for the first $1 million of valuation.
    • Sewer fees, applicable impact fees, and a $65 floodplain/wetland or individual lines-and-grades review fee may also apply.
    • The source also notes that plumbing, HVAC, refrigeration, and hood-ventilation permits may be required after permit issuance.

    building permit fee: per 12 USD per $1,000 valuation · certificate of occupancy fee: 60 USD · zoning permit fee: 10% of building permit fee USD ($21 minimum; $145 maximum) · Volunteer Fire Assistance Fund fee: 0.5 percent of valuation (applies to first $1 million of valuation) · floodplain/wetland or individual L&G review fee: per 65 USD per review (may apply to applicable projects)

    “Building Permit Fee: $12 per $1,000 of Valuation (refer to the Permit Valuation Computation Form) Certificate of Occupancy: $60”
  • Permit processPublished (with conditions)

    County building-permit and land-development review process in unincorporated New Castle County.

    • Applications and plans may be submitted electronically through eApply and ePlans.
    • Typical construction documentation includes lines-and-grades, drainage, sedimentation-and-erosion-control, sewage-disposal, building, mechanical, and plumbing documents.
    • Municipalities may administer permitting within incorporated areas.
    • Additional state, federal, or DelDOT approvals may be required depending on the project.
    “The Licensing Division of New Castle County Land Use issues permits for all construction in unincorporated areas. Typical documentation includes:”

Delaware rules that apply here

  • Who permits septicState

    On-site wastewater treatment and disposal systems in New Castle County, under Delaware statewide regulation.

    • DNREC administers the statewide septic approval process.
    • County land-use and sewer-connection rules may also impose additional conditions.
    “On-site wastewater treatment and disposal systems are governed by Delaware’s Regulations Governing the Design, Installation and Operation of On-Site Wastewater Treatment and Disposal Systems”
    One more reviewed finding on this topic
  • Septic permitRequired

    New or replacement on-site wastewater treatment and disposal systems in New Castle County.

    • A Class D soil scientist must prepare a site evaluation report for Department approval before a permit application.
    • A licensed system designer must design the system and obtain a permit.
    • Gravity-based systems use a Class B designer; engineered or pressure-dosed systems use a Class C designer.
    • Installation must be by a licensed Class E system contractor.
    “Any person applying for a permit to install a new or replacement on site wastewater treatment and disposal system”
    One more reviewed finding on this topic
  • Septic inspectionLimited

    Construction, repair, alternative-system operation, and ownership-transfer inspections for on-site wastewater systems in New Castle County.

    • For construction or repair, the inspector must inspect the installation unless the Department waives the pre-cover inspection under the stated conditions.
    • For transfers, the system must be pumped and inspected before completion of sale, subject to the stated 36-month, new-property certificate, or licensed-operator/service-contract exceptions.
    • Alternative systems require inspections by appropriately certified Class H inspectors; service contracts generally require inspection every six months unless otherwise approved.

    inspection report submission deadline: 72 hours after inspection completion · alternative-system inspection frequency: 6 months (unless otherwise approved by the Department)

    “The inspector shall inspect the installation”
    One more reviewed finding on this topic
  • Off-grid sanitationLimited

    Off-grid sanitation involving wastewater treatment, disposal, or holding systems serving property in New Castle County.

    • Delaware's statewide on-site wastewater regulations apply throughout the State, including New Castle County.
    • Plumbing fixtures from which wastewater is or may be discharged must connect to a central wastewater system or a Department-approved on-site wastewater treatment and disposal system.
    • Innovative or alternative systems may be approved where site constraints limit conventional systems, but the technology must provide at least an equivalent level of treatment and receive Department approval.
    • A septic-system approval requires a site evaluation, system design and permit, and installation by licensed professionals.
    • No Department permit may be issued unless the county or municipality having land-use jurisdiction first approves the activity through zoning procedures.
    • Untreated or partially treated wastewater discharge to the ground surface, groundwater, or surface waters is prohibited unless authorized by a Department permit.
    “All wastewater shall be treated and disposed of in a manner approved by the Department.”
    One more reviewed finding on this topic
  • Well permitRequired

    Construction and use of wells regulated under Delaware Administrative Code Regulation 7301 statewide.

    • Before well construction activities commence, the property owner or authorized agent must obtain prior DNREC approval in the form of a well permit.
    • A well may not be constructed until DNREC has issued both a well permit and a call-in authorization number, unless otherwise authorized under subsection 3.13.
    • A well permit is not required for hand augured soil borings or other soil borings that do not intersect the water table, such as direct push soil borings.
    • A well permit is required for construction and use of all wells and lysimeters.
    • A permit is not required for repair or rehabilitation of a well or associated equipment when the physical dimensions of the well are not changed; a change in physical dimensions or exceedance of original capacity requires a permit application.
    • Well construction, repair, modification, or sealing must be performed by or under the direct on-site supervision of a licensed well driller or well driver.
    • Well permit applications must include the applicable application fee and advertisement fee, if applicable.
    “Before any well construction activities commence to install any well, as defined in Section 2.0, the property owner or property owner’s authorized agent must obtain the prior approval of the Department to construct the well in the form of a well permit.”
    One more reviewed finding on this topic
    • Required — Water-well construction and use in New Castle County.
      “A well permit is required for the construction and use of all wells and lysimeters.”
  • Agricultural exemptionAvailable (with conditions)

    Qualifying farming and related activities regulated under Delaware’s wetlands chapter.

    • Farming is exempt only on lands where, in the prior 10 years on a rolling basis, normal activities were conducted for agricultural crops or there was an intent to farm for agricultural crops.
    • The activity must be part of an established and ongoing operation for farming and production of agricultural crops.
    • The exemption is from permit requirements and other regulation under Title 7, Chapter 66; it does not establish a general exemption from county or municipal zoning, building, septic, or other laws.
    • Silvicultural activities must be permitted by the Delaware Department of Agriculture.

    lookback period: 10 years on a rolling basis (The activity must be part of an established and ongoing farming operation.)

    “Farming on any lands upon which, in the prior 10 years on a rolling basis, normal activities have been conducted either a. For the farming and production of agricultural crops; or b. Manifesting an intent to farm the land for the production of agricultural crops, including but not limited to, activities such as plowing, seeding, clearing, irrigation installation, haying, grazing of domestic animals and free ranging livestock or poultry, cultivating, and harvesting; provided that such activity is part of an established and ongoing operation for the farming and production of agricultural crops.”
  • Campground & park staysProhibited

    Camping on lands administered by the Delaware Division of Fish and Wildlife.

    • Conservation-oriented groups may camp only with written permission of the Director and only in areas specified in the permit.
    “It shall be unlawful for any person to camp on lands administered by the Division, except conservation oriented groups may, with written permission of the Director, camp in areas specified in such permit.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission — ask the county directly.

  • Lot coverage — Lot coverage, impervious-surface, and open-space alternatives under current Chapter 40 Table 40.04.110 in unincorporated New Castle County
  • Living in an RV — Occupancy of a recreational vehicle as living quarters on private land in New Castle County, particularly in unincorporated areas.
  • Camping on your land — Temporary camping on private land in unincorporated New Castle County.
  • Short-term rentals — Short-term rental use in unincorporated New Castle County.

Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.

Water rights & wells in New Castle County

Whether a new home can legally get its own water here — the sub-state groundwater regime, from Delaware’s water agency.

Actively managed

This basin is under active state management — new water use is scrutinized, though a domestic well is usually still allowed.

Household wellPermit required (issued by right)

Delaware requires a state well permit for all wells statewide; every proposed location is screened for contamination within 1,000 ft, with a DNREC hydrologist review if a source is present. Withdrawals >50,000 gpd need a separate allocation permit.

Limit: DNREC well construction/use permit required for every new well (<=50,000 gpd)

DNREC Division of Water — Well Permits ↗
  • Delaware Groundwater Management Zones (contamination / saltwater)localized of county

    In mapped Groundwater Management Zones — concentrated in industrial New Castle County (e.g. the East Basin Road Superfund plume around New Castle's public wells and Delaware River-corridor saltwater-intrusion areas) — DNREC restricts or denies new potable wells and requires enhanced hydrologist review because of VOC/PFAS contamination or salt-water intrusion.

    DNREC Division of Water — Ground Water Protection ↗

Regulated-riparian state (large uses permitted). Groundwater rules change and basin boundaries follow the aquifer, not the county line — confirm current well and appropriation rules with the Delaware state water agency before you buy or drill.Groundwater governance as of Jul 2026, cited to each administering agency.

Living off-grid in New Castle County, Delaware

Is New Castle County a good place to live off-grid or homestead?

New Castle County scores 46/100 on the Bolthole Index, a marginal county profile. Its strengths: mixed durability signals and strong self-sufficiency basics: 46.1″/yr rainfall with little drought. Watch-outs: about 236,344 people within a 30-minute drive.

Do you need a building permit in New Castle County, Delaware?

New Castle County generally requires a residential building permit, and it enforces county zoning. Onsite septic is permitted by Delaware DNREC, Division of Water (Groundwater Discharges Section). Owner-builders may act as their own contractor to build their home. These answers are quoted from official sources and independently re-checked. Rules change and cities within the county differ — always confirm with the county before you buy or build.

How much does land cost in New Castle County, Delaware?

Land in New Castle County runs about $11,212 per acre, based on the latest county data.

What is the water situation in New Castle County?

New Castle County gets about 46.1" of rain a year, with severe drought in roughly 1.4% of years. On water rights, New Castle County lies in the Delaware Groundwater Management Zones (contamination / saltwater) — In mapped Groundwater Management Zones — concentrated in industrial New Castle County (e.g. the East Basin Road Superfund plume around New Castle's public wells and Delaware River-corridor saltwater-intrusion areas) — DNREC restricts or denies new potable wells and requires enhanced hydrologist review because of VOC/PFAS contamination or salt-water intrusion..

How remote is New Castle County?

A representative private-land location has about 236,344 people within a 30-minute drive and 14,997,054 within two hours. The road-network catchments count population across county lines and clusters of smaller cities; straight-line radius values remain available as a comparison.

How New Castle compares in Delaware

Compare side-by-side →See all 3 Delaware counties ranked →