Bolthole Index

Middlesex County, New Jersey

Building permits, zoning and septic rules in Dunellen, New Jersey

Building in the Borough of Dunellen, Middlesex County, New Jersey requires a construction permit under the state Uniform Construction Code, issued locally by the borough's Construction Office12. Zoning is set by the borough, not the county3. Septic work needs approval from the Middlesex County Environmental Health Division4.

At a glance

Building permit
Required under the state Uniform Construction Code; issued by the borough Construction Office12
Zoning
Yes, set by the borough; the county does not zone53
Certificate of occupancy
Required before use; a new one for each change of ownership, tenancy or use6
Septic
Approval from Middlesex County Environmental Health Division4
Accessory structure height
15 feet maximum in residential districts7
Flood areas
Floodplain development permit needed in designated flood hazard areas8
RV, tiny home
Not confirmed; ask the borough Zoning Officer2

Who to call

Building permits

Borough of Dunellen Construction Office

Construction permits, inspections and certificates of occupancy inside Dunellen

(732) 968-3323

355 North Avenue, Dunellen, NJ 08812

Septic permits

Middlesex County Environmental Health Division

Septic (individual subsurface sewage disposal) permits and inspections for Middlesex County

732-745-8480

Contact details are copied from each office’s official page and were checked against it on October 13, 2026.

Off-grid gear

Going off-grid in Borough of Dunellen means bringing your own water and power. The kit we’d start with:

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Do you need a building permit in Dunellen, NJ?

Yes, for most construction. New Jersey's Uniform Construction Code makes it unlawful to construct, enlarge, repair, alter or demolish a structure, or change its use, without first filing an application and obtaining the required permit9. Ordinary maintenance, such as routine repair, does not need a permit, and minor work needs a lighter "permit lite" process10.

Dunellen is not a rural exception: the state code applies the same way inside the borough, and the permit comes from the borough, not from Middlesex County1. Once work is finished and inspected, the borough also requires a certificate of occupancy, and a new one for any change of ownership, tenancy or use6.

Who issues building permits in Dunellen, and how do you reach them?

The Borough of Dunellen Construction Office issues construction permits and handles inspections. It is on the second floor of Borough Hall at 355 North Avenue, Dunellen, NJ 08812, and its phone number is (732) 968-33232.

Applications go to the local Construction Code Enforcement Office, and the state's application packet asks for one original plus three photocopies of each completed form11. The official must approve or deny a standard application within 20 business days12. Permit fees are set by municipal ordinance, so ask the Construction Office for the borough's current schedule13.

Does Dunellen have zoning, and what does it mean for RVs, tiny homes and setbacks?

Yes. Zoning in New Jersey belongs to municipalities, and Middlesex County has no zoning power3. Dunellen adopts its own zoning chapter, and a certificate of occupancy certifies that a structure complies with it6.

Some numbers you can use: in any residential district, an accessory structure may not exceed 15 feet to its highest point7, and a residential driveway must sit at least 2 feet from the side property line14. Lot size, setbacks and home size vary by district under the state's Municipal Land Use Law1516.

We could not confirm Dunellen's rules for living in an RV, tiny homes or accessory dwellings. Ask the borough Construction Office or Zoning Officer before you buy or place anything2.

How do septic permits work in Dunellen?

Septic work in Middlesex County needs approval from the Middlesex County Environmental Health Division4. State law also bars issuing a building permit until the board of health certifies that the water supply and sewerage facilities comply, and a septic system may not be covered until a board of health representative inspects it1718.

We could not confirm whether a given Dunellen lot is on public sewer or would need a septic system. Call the county health division at 732-745-8480 and the borough Construction Office before you plan on either4. Private wells need a state drilling permit plus a municipal or county health permit19.

Building a home in Dunellen: the steps, in order

  1. Confirm the zoning district and what the lot allows with the borough Construction Office2.
  2. If the lot is near a stream or in a mapped flood hazard area, get the state permit and a borough floodplain development permit first8.
  3. Settle sewer or septic: the county health division for septic4.
  4. Apply for the construction permit with plans; the state says no permit issues until all required state, county and local approvals are in place20.
  5. Call for inspections as work progresses, including footings, rough plumbing and electrical, and framing21.
  6. Obtain the certificate of occupancy before anyone moves in6.

What stays with Middlesex County, and what to check before you buy in Dunellen?

The county does not issue building permits or zone land; its planning board reviews subdivisions and site plans, particularly those touching county roads or drainage, and that review does not replace borough approvals22. A driveway onto a state highway needs a state access permit23. For land outside the borough, see the Middlesex County page.

Budget for taxes: Middlesex County's effective property tax rate is 2.2% and the median bill is $9,684 a year2425.

Watch-outs

  • Owner-builders still need construction permits; the state's owner-builder provision concerns builder registration and a disclosure affidavit before the certificate of occupancy, not a permit exemption26.
  • Flood hazard areas and riparian zones inside Dunellen need a floodplain development permit and, where the borough's chapter says so, a state DEP permit first8.
  • We could not confirm Dunellen's rules for RVs, tiny homes or accessory dwellings; ask the Construction Office before relying on any of them2.

Sources

  1. NJ Dept of Community Affairs — The NJ State Uniform Construction Code (2026 county census)
  2. Borough of Dunellen Construction Office (dunellen-nj.gov)
  3. P.L. 2013, c.106 — Municipal Land Use Law amendments (New Jersey statewide rule), quoted and re-checked
  4. Middlesex County Environmental Health Division (middlesexcountynj.gov)
  5. NJ Dept of Community Affairs — Uniform Construction Code (2026 county census)
  6. Chapter 115 Zoning, Article IV (Borough of Dunellen), quoted and re-checked
  7. Chapter 115 Zoning, Article II (Borough of Dunellen), quoted and re-checked
  8. Chapter 165 Flood Damage Prevention (Borough of Dunellen), quoted and re-checked
  9. N.J.A.C. 5:23-2.14, Construction permits—when required (New Jersey statewide rule), quoted and re-checked
  10. Construction Permit Application Packet & Related Forms, quoted and re-checked
  11. Construction Permit Application Packet & Related Forms, quoted and re-checked
  12. N.J.A.C. 5:23 Uniform Construction Code, quoted and re-checked
  13. The New Jersey State Uniform Construction Code (New Jersey statewide rule), quoted and re-checked
  14. ecode360.com (Borough of Dunellen), quoted and re-checked
  15. P.L. 2013, c.106 (Municipal Land Use Law amendments) (New Jersey statewide rule), quoted and re-checked
  16. P.L. 2013, c.106 (Municipal Land Use Law amendments) (New Jersey statewide rule), quoted and re-checked
  17. New Jersey Statutes, R.S. 58:11-23 through 58:11-43 (New Jersey statewide rule), quoted and re-checked
  18. New Jersey Statutes, R.S. 58:11-23 through 58:11-43 (New Jersey statewide rule), quoted and re-checked
  19. Bulletin 88-10: Private On-Site Water Supply Systems (New Jersey statewide rule), quoted and re-checked
  20. New Jersey Uniform Construction Code, N.J.A.C. 5:23 (New Jersey statewide rule), quoted and re-checked
  21. New Jersey Department of Community Affairs, New Home Warranty—Consumer Information (New Jersey statewide rule), quoted and re-checked
  22. Middlesex County Planning Board Resolution 2025-13 and Land Development Standards Chapter 400, quoted and re-checked
  23. Major Access Permits (New Jersey statewide rule), quoted and re-checked
  24. Effective property tax rate: Bolthole Index county data
  25. Median property tax bill: Bolthole Index county data
  26. Builder Registration and New Home Warranty for Builders (New Jersey statewide rule), quoted and re-checked

Written October 13, 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.

Answers from the rulebook for Borough of Dunellen

Borough of Dunellen’s own rules

  • Certificate of occupancyRequired

    Any building or premises created, located, erected, changed, converted or enlarged inside Dunellen borough.

    • A new certificate is required for every change of ownership, tenancy or use.
    • The certificate must certify compliance with the zoning chapter.
    “Certificates of occupancy. It shall be unlawful to use or permit the use of any building or premises or part thereof hereafter created, located, erected, changed, converted or enlarged wholly or partly until a certificate of occupancy has been issued by the Borough of Dunellen for the premises certifying that the structure complies with the provisions of this chapter. A new certificate of occupancy shall be required for any and all changes of ownership, tenancy or use.”
  • Driveway accessRequired

    Principal buildings constructed inside Dunellen borough.

    • The lot must front on a public street improved under Borough requirements, or the improvements must be insured by a performance guaranty.
    • Residential driveways must be set back at least two feet from the side property line.

    minimum residential driveway side setback: >= 2 feet

    “A residential driveway shall be set back a minimum of two feet from the side property line.”
  • Building in a floodplainRequired

    Proposed development in designated flood hazard areas inside Dunellen borough.

    • The chapter operates together with the Uniform Construction Code flood provisions and New Jersey Flood Hazard Area Control Act rules.
    • Development in riparian zones is prohibited unless the applicant obtains the specified NJDEP permit, permit-by-rule or permit-by-certification and complies with the Borough's other floodplain provisions.
    “All development in riparian zones as described in N.J.A.C. 7:13 is prohibited by this chapter unless the applicant has received an individual or general permit or has complied with the requirements of a permit by rule or permit by certification from NJDEP Division of Land Resource Protection prior to application for a floodplain development permit and the project is compliant with all other floodplain development provisions of this chapter.”
  • Permit processPublished (with conditions)

    Planning, zoning, subdivision and site-plan applications inside Dunellen borough.

    • Required documents must generally be submitted electronically as prescribed by the Planning Board Secretary or designee.
    • One official hard copy, one courtesy hard copy and signed and sealed plans must also be submitted.
    • The Planning Board Secretary may require additional hard copies.
    “Unless otherwise specifically provided herein, all documents required to be submitted under the Land Development Ordinance shall be submitted electronically in the manner prescribed by the Planning Board Secretary or designee. The prescribed manner shall be set forth on the Borough's website for public dissemination.”

Rules another office applies inside Borough of Dunellen

Borough of Dunellen does not set these itself; the county, a health district or the state does, and they apply to every address inside its limits.

  • Building heightDistrict specific (with conditions)

    Building heights in Dunellen borough zoning districts.

    • The numeric district schedule was not reproduced in the reviewed webpage.
    • Accessory structures in residential districts may not exceed 15 feet to the highest point.

    maximum accessory-structure height in residential districts: <= 15 feet (highest point of structure)

    “In any residential district, no accessory structure shall exceed 15 feet in height to the highest point of the structure.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Borough of Dunellen or Middlesex County directly.

  • Building permit — Building work inside Dunellen borough.
  • Owner-builder exemption — Owner-builders performing construction inside Dunellen borough.
  • Living in an RV — Occupancy of recreational vehicles as residences inside Dunellen borough.
  • Camping on your land — Temporary camping on private land inside Dunellen borough.
  • Tiny homes — Tiny-home occupancy inside Dunellen borough.
9 more unanswered
  • Manufactured homes
  • Accessory dwellings
  • Who permits septic
  • Septic permit
  • Septic inspection
  • Off-grid sanitation
  • Well permit
  • Mandatory utility hookup
  • Agricultural exemption

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.

Unanswered questions are usually a sign that Borough of Dunellen publishes no rule on the point, not that none exists. Middlesex County’s page lists the county offices to call.

← All of Middlesex County: county rules, score and offices