Building permits, zoning and septic rules in Jefferson Parish, Louisiana

Yes. Unincorporated Jefferson Parish requires all required permits to be in hand before regulated construction, alteration, repair, movement, demolition or a change of occupancy begins¹. Electrical, gas, mechanical and plumbing work covered by the technical codes requires a properly licensed applicant and an inspection filing before work starts^1,9. Minor work and ordinary repairs may usually be exempt, but the code official may still require a permit and inspection when a condition is hazardous or complex¹. Residential permit plans must identify the applicable reference code and comply with Jefferson Parish's adopted code amendments⁵. An owner applying for a building permit on a personal residence may claim a licensing exemption by filing the parish affidavit; this does not remove building-permit or inspection requirements^1,5.

The Jefferson Parish Building Permits Department is the building department for unincorporated Jefferson Parish². Its East Bank office is at 1221 Elmwood Park Boulevard, Suite 101, Jefferson, and its West Bank office is at 1855 Ames Boulevard, Suite A, Marrero². Call the East Bank office at 504-736-6957 for residential or commercial building-permit questions². Permit Navigators serve as applicant contacts and follow building permits through review². Engineering automatically reviews every building permit filed for a new single-family dwelling, two-family dwelling, townhouse, manufactured home or modular home; applicants no longer submit the former Public Works infrastructure-assurance form⁵. Required inspections still apply to permitted technical-code work, although qualifying reroofing work may use geotagged photographs instead of an in-person inspection¹. A new building cannot be occupied, and an existing building's use or occupancy cannot change, until the Building Permits Director issues a Certificate of Use or Occupancy, subject to the ordinance's exception¹⁰.

Yes, in unincorporated Jefferson Parish. Parish zoning regulates land use, building size and placement, yards and parking by district; Kenner, Gretna, Harahan, Westwego, Lafitte and Grand Isle are outside the parish zoning map and their own jurisdictions answer zoning questions³. Ask the Planning Department at 504-736-6320 to confirm the current district and standards for a parcel¹¹. Rules vary sharply by district and study area. For certain R-1A, R-1B and S-1 properties in the Leo Kerner/Lafitte Parkway study area, interim setbacks are 50 feet in front, 25 feet in back and 15 feet on each side¹². Those standards were adopted for one year beginning October 22, 2025 and may be extended once for six months, so confirm their current status before relying on them¹².

Septic permitting in Jefferson Parish is handled by the Louisiana Department of Health through the parish health unit, not by the parish building department⁴. Louisiana requires a state health officer's permit before an individual sewerage system is installed, altered or operated¹³. A septic tank system may be used only where a community sewer is unavailable, while a mechanical treatment plant requires a finding that a conventional system would not work properly¹³. Jefferson Parish has no mapped soil share rated without severe limits for a conventional drain field, so a site evaluation and a nonconventional design may be necessary¹⁴. Final approval requires either a state on-site inspection or a licensed installer's completed certification form¹³. Start with Environmental Health Services at the Jefferson Parish Health Unit before designing the house or buying septic equipment¹⁵.

Jefferson Parish's general rule for living in an RV or a stand-alone tiny home on private land could not be confirmed, so ask the Planning Department about an unincorporated parcel or the relevant municipality about land inside its limits^3,11. A mobile or manufactured home is conditionally allowed under the cited RR-3 rule only when the applicable criteria are met and approval is obtained; that rule is not parishwide permission⁷. An accessory dwelling unit has a clearer path: it requires a conditional zoning map amendment and building permit, must serve a qualifying primary residence, and cannot be an RV, travel trailer or mobile home⁶. Only one accessory dwelling is allowed per lot; it must be at least 400 square feet and no larger than half the principal building or 1,000 square feet, whichever cap applies⁶. The underlying district's side-yard setback applies along the accessory dwelling's rear and side yards, and the unit cannot occupy the required front yard⁶.

1. Confirm the zoning authority, district and current dimensional standards with the Jefferson Parish Planning Department or the municipality where the lot lies^3,11.
2. Ask whether public water and sewer serve the lot; a new parish utility connection requires an application, review, fees and sometimes more documents¹⁶.
3. If sewer is unavailable, contact the Jefferson Parish Health Unit for the state septic permit and site evaluation^13,15.
4. Ask Floodplain Management what elevation and floodplain requirements apply before finalizing plans^5,17.
5. Include a parish driveway-permit application with a new-home building permit when the apron meets parish right-of-way; a state-road connection instead needs a Louisiana Department of Transportation and Development driveway permit⁸.
6. File the building-permit application and, if building a personal residence as an owner-builder, the licensing-exemption affidavit with the Building Permits Department before work begins^1,2,5.
7. Complete the required building-system inspections, obtain septic final verification and secure the Certificate of Use or Occupancy before occupying the new building^1,10,13.

Check zoning, legal-lot status, utilities, flood requirements and access before closing. The Jefferson Parish Planning Department reviews subdivision applications and makes recommendations, while a qualifying minor subdivision in unincorporated Jefferson Parish can use administrative approval only when it stays within 10 lots and 2 acres; a major subdivision requires public hearings^18,19. Planning fees vary by application, so schedule the recommended pre-application conference rather than budgeting from one fee alone²⁰. Verify actual utility availability and connection costs; the published total for a residential three-quarter-inch meter is $1,130, including deposit, installation and sewerage charges¹⁶. Floodplain rules can impose building-height requirements, and development in a regulatory floodway may need a no-rise demonstration^5,21. A conventional drain field faces severe soil limitations throughout the mapped parish area¹⁴. Identify whether the driveway meets parish or state right-of-way because each has a separate driveway-permit path⁸.