Building permits, zoning and septic rules in Union County, New Jersey

Covered new construction and work on existing buildings in Union County requires a building permit under New Jersey's statewide Uniform Construction Code; ordinary maintenance is excepted^1,2. For a new private single-family residence built for the owner's own occupancy, the owner may perform or supervise construction, plumbing and electrical work under applicable laws and assumes responsibility for that work and subcontractors¹³. A complete municipal building-permit application must be released or denied within 20 business days¹. An owner building a one- or two-family dwelling must file the prescribed affidavit acknowledging that owner-performed or owner-supervised work lacks New Home Warranty and Builders' Registration Act coverage, and disclose that lack of coverage to buyers within 10 years after the Certificate of Occupancy^9,14. Owner-building does not waive the building permit or code requirements⁹.

The parcel's municipal Construction Code Enforcement Office issues building permits and enforces the statewide UCC^1,2. Inside Elizabeth, the Borough of New Providence, the Borough of Fanwood and the Borough of Mountainside, the municipality's own office handles building permits^15,16,17,18. Septic approval remains a separate health-authority responsibility under state law⁴. Union County reviews subdivision applications before municipal approval and requires county approval when county roads or drainage facilities are affected⁵. Call the County Planning Board at 908-527-4268 for county development review, or the general information line at 908-527-4000 for routing help^3,19. Building-permit fees are set by each municipality's ordinance, so there is no single countywide residential fee; get the schedule from the parcel's construction office¹. County review of a subdivision costs $200 for a minor subdivision that does not abut a county road or affect county drainage, $300 if it does, and $400 or $500 plus $20 per lot for a major subdivision on the same split²⁰. County road-opening permits carry a $30 application fee for a normal opening and a $40 permit fee for up to 20 square feet²¹.

Union County does not enact the zoning ordinance for your parcel; municipal land-use rules apply, while County Planning keeps local zoning ordinances on file^3,6. Municipalities that adopt and administer their own zoning include Plainfield²², Linden²³, Rahway²⁴, the Borough of Roselle²⁵, the Borough of Roselle Park²⁶, the Borough of Kenilworth²⁷, the Borough of Fanwood²⁸, the Borough of Garwood²⁹, the Borough of Mountainside¹⁸ and Union Township³⁰, as well as Berkeley Heights, Clark, Hillside, Scotch Plains and Springfield townships^{31,32,33,34,35}. Septic certification still comes from the board of health with jurisdiction, separately from zoning approval⁴. Union County's GIS layer labeled County Zoning does not establish a parcel's allowed uses or dimensions⁷. Ask the municipal zoning officer for the parcel's district and permitted use; lot size, setbacks, coverage, height and dwelling floor area can vary by district^3,10.

Before a building permit can issue for a Union County property needing septic facilities, the board of health with jurisdiction must certify the proposed water supply and sewerage facilities⁴. Local health authorities generally oversee ordinary septic systems, while NJDEP handles specified treatment-works approvals and discharges over 2,000 gallons per day⁸. Mountainside lists septic permits for new systems, repairs and abandonment³⁶, and Linden's construction official requires proof of health-department approval of the septic plan before issuing a construction permit³⁷. We could not confirm a single countywide septic counter or fee schedule; ask the parcel's municipality which health authority serves the address. Septic facilities must be inspected by the board of health's authorized representative and approved before covering⁴. About 5.2% of Union County soils are rated not limited for conventional septic drain fields; that rating supports early site evaluation, not a conclusion that septic is impossible elsewhere³⁸.

New Jersey's residential construction code recognizes tiny houses within its rules for detached homes, so a code-compliant tiny house can be used as a dwelling in Union County if it also secures municipal land-use, utility, septic and other required approvals¹¹. Municipal ordinances still control where a tiny house may go and can set district-specific floor area, lot size, setbacks, lot coverage and height rules^3,10. We could not confirm a countywide rule allowing long-term RV occupancy or temporary camping on private land, so ask the parcel's municipal zoning officer before relying on an RV as temporary or permanent housing. A manufactured HUD home used as a dwelling is limited to the single-family R-5 use group and has federal installation requirements, but that does not establish municipal zoning approval for a particular parcel³⁹.

1. Identify the parcel's municipality because its zoning ordinance and construction-code office control the first approvals^1,3.
2. Ask the municipal zoning officer to confirm the district, permitted use, lot size, setbacks, coverage, height and dwelling-size rules¹⁰.
3. For a subdivision, submit the application to the Union County Planning Board before municipal approval; county approval is required when county roads or drainage facilities are affected^3,5.
4. If public sewer is unavailable, identify the local health authority and obtain septic certification before the building permit⁴.
5. Request the municipal building-permit fee schedule and submit the applicable technical forms to the local Construction Code Enforcement Office¹.
6. Obtain every required state, county and local prior approval before the building permit is issued⁹.
7. Schedule required building inspections before covered work is concealed².
8. Complete final inspections so the local construction official can issue the Certificate of Occupancy².

For a Union County subdivision, submit the sketch plat to the county before municipal action; municipal approval remains required even if the county grants an exemption from further review⁴⁰. One exemption route requires no more than 3 lots, no county-road frontage and no adverse drainage condition as determined by the County Engineer; another concerns whether a county master-plan road or drainage right-of-way will affect the subdivision⁴⁰. A subdivision with 3 or fewer lots abutting a county road remains subject to preliminary county review concerning roads or drainage⁴⁰. Recording a subdivision plat requires municipal approval, the required municipal signatures and seals, and County Planning Board approval; county review does not replace municipal approval³. For a private well, NJDEP requires a drilling permit and local health officials handle well-construction approval⁴¹. Access onto a state highway requires an NJDOT access permit¹².