Bolthole Index

Mercer County, New Jersey

Building permits, zoning and septic rules in Pennington Borough, New Jersey

Pennington Borough in Mercer County, New Jersey requires a construction permit from the borough's code enforcement office before you build or alter a structure, and a new building also needs zoning approval1. The borough adopts and applies its own zoning chapter2. Septic and other health services come through the Pennington Borough Board of Health with the Hopewell Township Health Department3.

At a glance

Building permit
Required; a new building needs building, fire, electrical, plumbing and zoning approvals1
Who issues it
Pennington Borough code enforcement office, not Mercer County14
Zoning
Set by the borough (Chapter 215 of the borough code)2
Septic
Board of Health with the Hopewell Township Health Department; public sewer connection is required where a borough sewer abuts35
Plan review fee
10% of the construction permit fee, $75 minimum6
Accessory apartment
Affordable accessory apartments only, in R-80 and R-100 districts7
Owner-builder
Exempt from builder registration, not from permits8

Who to call

Building permits

Pennington Borough Hall (code enforcement, zoning and Board of Health)

Construction permits and zoning approvals inside Pennington Borough, applied for at the borough's code enforcement office.

(609) 737-0276

30 North Main Street, Pennington, NJ 08534-0095

Septic permits

Hopewell Township Health Department

Septic system permits and private-well testing for the Hopewell Valley, which includes Pennington Borough.

609-737-0120

201 Washington Crossing - Pennington Road, Lower Level, Titusville, NJ 08560

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 Pennington means bringing your own water and power. The kit we’d start with:

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Do you need a building permit in Pennington, NJ?

Yes. Pennington Borough requires a construction permit, which may include building, electrical, fire and plumbing sections, for new buildings, additions, alterations and many smaller jobs1. A new building needs building, fire, electrical, plumbing and zoning approvals, with prior approval for a new dwelling9. New Jersey's Uniform Construction Code requires a permit for new construction and for repair, renovation, alteration or demolition, with an exception for ordinary maintenance10.

Building homes for yourself does not remove that requirement: the statewide owner-builder exemption covers builder registration only, not construction permits or code compliance8.

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

The borough's code enforcement office at Borough Hall takes construction permit applications9. Mercer County does not issue them; fees and schedules are set by each municipality4. Borough Hall is at 30 North Main Street and can be reached at (609) 737-02769.

Plan review is charged at 10% of the construction permit fee, with a $75 minimum6. The borough also publishes zoning application fees; its zoning application says the fee schedule is attached6.

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

Yes. Chapter 215 of the borough code is Pennington's zoning chapter, adopted by the Borough Council2. Mercer County has limited jurisdiction over local land-use decisions, and zoning standards are set municipally11.

The borough's permit page lists trailer placement and temporary mobile homes as permit categories1, but we could not confirm a rule on living in an RV, camping on private land or tiny-home occupancy in Pennington. Ask the borough code enforcement office and zoning office before you buy.

One accessory-dwelling path exists: a single affordable accessory apartment on a conforming lot in the R-80 or R-100 district, rented to a low-income household, with no more than six borough-wide7.

How do septic permits work inside Pennington?

Septic and related environmental-health services in Pennington come through the Pennington Borough Board of Health, working with the Hopewell Township Health Department3. Municipal or county health boards enforce septic requirements in New Jersey, and the building official requires health department approval of the septic plan before issuing a construction permit1213.

Many Pennington properties may not be allowed a septic system at all. The borough code makes it unlawful to maintain a septic tank or similar facility, with exceptions, and requires connection to the public sewer within 270 days of official notice where a borough sewer abuts the property145. Septic tanks must be abandoned and filled once a connection is made5.

Building a home in Pennington: the steps, in order

  1. Confirm your lot's zoning district and any zoning approval with the borough2.
  2. Ask the borough whether a public sewer abuts the lot; if not, get septic plan approval from the health department first513.
  3. File a construction permit application with the borough code enforcement office; a new building needs building, fire, electrical, plumbing and zoning approvals9.
  4. Build with the required inspections, which stop work at set points such as footings and rough plumbing before framing15.
  5. Obtain a certificate of occupancy for a new building16.

What stays with Mercer County, and what to check before you buy

Mercer County does not zone or issue building permits inside Pennington114. Land outside the borough follows different municipal rules; see the Mercer County page.

Check taxes: Mercer County's effective property tax rate is about 2.5%17. Mercer County farmland averages about $26,811 per acre18. Only about 10.9% of Mercer County soils rate as not limited for a conventional septic drain field, so expect a site evaluation19.

Watch-outs

  • Do not assume a lot can have a septic system: where a borough public sewer abuts a property, the code requires connection within 270 days of notice5.
  • We could not confirm Pennington's rules on RV occupancy, camping or tiny homes; ask the borough code enforcement office, which handles zoning approvals, before buying for that use9.
  • An owner-builder exemption covers builder registration only; construction permits are still required8.
  • The state's 2024 construction code amendments took effect on August 17, 202620.

Sources

  1. When is a Permit Needed? (Borough of Pennington), quoted and re-checked
  2. Chapter 215 Zoning (Borough of Pennington), quoted and re-checked
  3. Board of Health (Borough of Pennington), quoted and re-checked
  4. The New Jersey State Uniform Construction Code, quoted and re-checked
  5. Chapter 159 Sewer Use (Borough of Pennington), quoted and re-checked
  6. Article XV Uniform Construction Code Fees (Borough of Pennington), quoted and re-checked
  7. Article IX Exceptions—Affordable accessory apartments (Borough of Pennington), quoted and re-checked
  8. N.J.A.C. 5:25-2.1 Registration required, quoted and re-checked
  9. Pennington Borough Hall (code enforcement, zoning and Board of Health) (penningtonboro.org)
  10. The New Jersey State Uniform Construction Code, quoted and re-checked
  11. Mercer County Water Quality Management Plan, quoted and re-checked
  12. Bulletin 79-7: Septic Systems, quoted and re-checked
  13. Bulletin 79-7: Septic Systems, quoted and re-checked
  14. Chapter 159 Sewer Use (Borough of Pennington), quoted and re-checked
  15. New Jersey Department of Community Affairs, New Home Warranty—Consumer Information (New Jersey statewide rule), quoted and re-checked
  16. N.J.A.C. 5:23, Uniform Construction Code (New Jersey statewide rule), quoted and re-checked
  17. Effective property tax rate: Bolthole Index county data
  18. Farmland value per acre (USDA census): Bolthole Index county data
  19. 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
  20. Current Construction Codes (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 Pennington

Borough of Pennington’s own rules

  • Building permitRequired

    Construction and listed building, alteration, addition, new-building, trailer-placement, and temporary-mobile-home work inside Pennington borough.

    • The official page says a construction permit may include building, electrical, fire, and plumbing subcode sections.
    • A new building requires building, fire, electrical, plumbing, and zoning approvals, with prior approval for a new dwelling.
    • Requirements vary by project.
    “A construction permit, which may include a building, electrical, fire and/or plumbing sub-code technical section, is required to do any of the following:”
  • Local zoningPresent

    Land inside Pennington borough.

    • Chapter 215 is the borough's zoning chapter; the code states it was adopted by the Borough Council on 8-7-1978 by Ordinance 295.
    “[HISTORY: Adopted by the Borough Council of the Borough of Pennington 8-7-1978 by Ord. No. 295. Amendments noted where applicable.]”
  • Accessory dwellingsAllowed (with conditions)

    One affordable accessory apartment on a lot in the R-80 or R-100 zoning district inside Pennington borough.

    • The lot must fully conform to minimum lot area and minimum lot width requirements.
    • The lot must have only one single-family detached dwelling.
    • The apartment must be rented to a low-income household for at least 10 years from certificate-of-occupancy issuance.
    • No more than six affordable accessory apartments are permitted borough-wide.
    • The apartment must contain at least 350 and no more than 800 square feet.

    maximum borough-wide affordable accessory apartments: 6 apartments · minimum apartment area: >= 350 square feet · maximum apartment area: <= 800 square feet · low-income rental period: >= 10 years from certificate of occupancy

    “Where permitted. Notwithstanding any provision of this section to the contrary, one affordable accessory apartment shall be permitted on a lot within the R-80 and R-100 Zoning Districts which meets the following requirements:”
  • Off-grid sanitationLimited

    Private sewage-disposal facilities and off-grid sanitation inside Pennington borough.

    • The code prohibits maintaining privies, privy vaults, septic tanks, or other sewage-disposal facilities except as otherwise provided.
    • Where a borough public sewer abuts the property, direct connection is required.
    “Except as hereinafter provided, it shall be unlawful to construct or maintain any privy, privy vault, septic tank, cesspool or other facility intended or used for the disposal of sewage.”
  • Mandatory utility hookupSewer (with conditions)

    Houses, buildings, and properties used for human occupancy, employment, recreation, or other purposes inside Pennington borough that abut a street, alley, or right-of-way containing a borough public sanitary sewer.

    • Connection is at the owner's expense.
    • Connection must occur within 270 days after official notice.
    • When connection is made, septic tanks, cesspools, and similar private sewage facilities must be abandoned and filled as provided by the code and applicable state laws and sanitary codes.

    connection deadline: 270 days after official notice

    “The owner of all houses, buildings or properties used for human occupancy, employment, recreation or other purpose, situated within the borough and abutting on any street, alley or right-of-way in which there is located a public sanitary sewer of the borough, is required at the owner's expense to connect directly with the proper public sewer in accordance with the provisions of this chapter within 270 days after the date of official notice to do so.”
  • Permit feesPublished

    Construction and zoning-related permits inside Pennington borough.

    • Plan review is 10% of the construction-permit fee, with a $75 minimum.
    • Zoning application fees include residential fence $28, residential principal use $66, residential accessory use $33, commercial fence $55, commercial principal use $165, commercial accessory use $66, signs $25, temporary activity permit $55, and residential conversion $110.
    • The zoning application says the fee schedule is attached.

    minimum plan review fee: 75 USD · plan review fee: 10 percent of construction permit fee (20% DCA plan-review fee deducted under N.J.A.C. 5:23-2.26)

    “Plan review fees shall be computed at 10% of the fee to be charged for the construction permit. For projects which do not require plan review for all subcodes, the fee shall be the appropriate percentage of the subcode fee that is applicable. The minimum plan review fee is $75.”

Rules another office applies inside Borough of Pennington

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

  • Who permits septicMixed (with conditions)

    Septic and related environmental-health services inside Pennington borough are provided through the Pennington Borough Board of Health in conjunction with the Hopewell Township Health Department; municipal sewer connections remain administered by the borough Sewer Department.

    • The health department serves the Hopewell Valley, including Pennington borough.
    • The borough code separately governs connection to public sanitary sewer.
    “We work in conjunction with the Hopewell Township Health Department to provide day-to-day public health services to Pennington Borough pursuant to New Jersey’s Public Health Practice Standards”

Still unanswered

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

  • Owner-builder exemption — Owner-builder work inside Pennington borough.
  • Living in an RV — Residential or long-term occupancy of recreational vehicles inside Pennington borough.
  • Camping on your land — Temporary camping on private land inside Pennington borough.
  • Tiny homes — Tiny-home occupancy inside Pennington borough.
  • Manufactured homes — Manufactured-home occupancy inside Pennington borough.
3 more unanswered
  • Agricultural exemption
  • Driveway access
  • Short-term rentals

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 Pennington publishes no rule on the point, not that none exists. Mercer County’s page lists the county offices to call.

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