Unincorporated St. Tammany Parish, Louisiana requires a building permit for residential new construction through the Department of Permits and Inspections1. The parish also has zoning, while on-site wastewater work goes through Environmental Services' Sewerage Inspection Permit program23. An owner may serve as builder for a primary residence, subject to the parish affidavit's conditions4.
At a glance
- Building permit
- Required for residential new construction in unincorporated areas1
- Zoning
- Yes — confirm the parcel's published zoning classification25
- Septic permit
- Applicable systems require an online parish Sewerage Inspection Permit application3
- RV living
- A parish-wide private-land rule was not confirmed; ask Planning & Development26
- Tiny home
- Occupancy and minimum-size answers depend on rules for the parcel27
- Owner-builder
- Allowed for a primary residence, limited to one home in a two-year period4
- Private well
- Licensed installation and state registration are required8
Who to call
Building permits
St. Tammany Parish Department of Permits and Inspections
Building-code enforcement, permits and inspection questions
21454 Koop Drive, Building B, Mandeville, LA 70471
Zoning
St. Tammany Parish Department of Planning & Development
Planning, zoning and parcel-specific land-use questions
21454 Koop Dr Building B, Mandeville, LA 70471
Septic permits
St. Tammany Parish Department of Environmental Services
Sewerage Inspection Permit applications and on-site wastewater inspections
21454 Koop Drive, Building B, Mandeville, LA 70471
Contact details are copied from each office’s official page and were checked against it on September 28, 2026.
Do you need a building permit in St. Tammany Parish, Louisiana?
Yes. Unincorporated St. Tammany Parish requires a building permit for residential new construction through the Department of Permits and Inspections1. Louisiana requires parishes and municipalities to enforce the State Uniform Construction Code for covered work, with enforcement procedures that include plan review and permit decisions9. The parish office directs applicants to its online permit system and answers questions about applications, fees, inspections, flood zones and utility-connection permits10. An owner-builder path is available when the owner will occupy the single-family dwelling as a primary residence, but the parish affidavit limits that path to one single-family residence in a two-year period4.
Who is the St. Tammany Parish building department?
The St. Tammany Parish Department of Permits and Inspections handles building-permit and inspection questions10. Its office is at 21454 Koop Drive, Building B, Mandeville, LA 70471, and its listed phone number is 985-898-257410. The published application workflow starts at MyPermitNow, where a new applicant creates a customer account1110. Planning and zoning questions go to the separate Department of Planning & Development at 21454 Koop Dr Building B, Mandeville, LA 70471, phone 985-898-25296. Ask the building office which plan documents and reviews apply, and ask Planning & Development to confirm the parcel's zoning classification before finalizing a design106.
Does St. Tammany Parish have zoning?
Yes. St. Tammany Parish has a Unified Development Code, and the parish publishes mapped zoning classifications25. Louisiana law allows parish zoning to regulate structure size and height, lot occupancy, density, open space, and land and building uses12. Setbacks, height, lot coverage, RV use, tiny homes and minimum dwelling size therefore depend on the classification and rules for the specific parcel, not a single number that works parish-wide21314157. The Department of Planning & Development is the office to ask for a parcel-specific interpretation before purchase or design6.
How do septic permits work in St. Tammany Parish?
St. Tammany Parish Environmental Services administers the Sewerage Inspection Permit program and issues permits and conducts inspections for on-site wastewater systems1617. Applicable applications must be submitted online, and the parish page lists a $100 payment amount for checks and money orders318. Louisiana requires a permit before an individual sewerage system is installed, altered or operated, and a septic tank may be used only where a community sewer system is unavailable and sanitary-code requirements are met1920. Only about 1.2% of parish soils are rated without severe limitations for a conventional drain field, so make septic feasibility an early contingency21.
Can you live in an RV or tiny home in St. Tammany Parish?
We could not confirm a parish-wide rule allowing long-term RV occupancy, temporary private-land camping or tiny-home occupancy in unincorporated St. Tammany Parish. Because the parish has zoning, ask Planning & Development whether the parcel's classification allows the proposed RV or tiny-home use and what placement, utility and dimensional rules apply26. Louisiana does not supply one statewide minimum dwelling size through the cited zoning authority; a size rule may instead come from the applicable local district7. State-park camping limits do not answer the private-property question because those limits apply to Office of State Parks facilities22. A tiny home used as a dwelling still needs an approved wastewater path where an individual system is involved19.
Building a home in St. Tammany Parish: steps in order
- Ask Planning & Development to confirm the parcel's zoning classification and proposed residential use65.
- Confirm sewer availability; if an individual system is needed, file the online Sewerage Inspection Permit application and arrange inspections31720.
- Create an online permit account and submit the building application through the parish workflow1110.
- If acting as builder, complete the affidavit and verify that its primary-residence and frequency conditions fit4.
- For access to a Louisiana state highway, obtain the signed and numbered state permit before construction23.
- Complete building and wastewater inspections; final wastewater approval requires installation verification1724.
What should you check before buying land in St. Tammany Parish?
Check zoning, sewer availability, septic feasibility, flood constraints and legal road access before the inspection period expires2202523. Conventional drain fields face severe soil limitations across nearly all of the parish, with only about 1.2% of soils rated without severe limitations21. Development in a regulatory floodway may need technical support showing no rise, while a project that causes a rise must be changed, compensated for or obtain a community-requested revision before permitting and development25. A new private well must be installed by a licensed contractor and registered with the state after completion, while domestic wells follow the cited post-installation notification exception8. The effective property-tax rate is about 0.7%, and the median annual bill is about $2,0052627.
Watch-outs
- Owner-builders must intend to occupy the home as a primary residence and may use the affidavit path for no more than one single-family residence in a two-year period4.
- We could not confirm one parish-wide answer for private-land RV living, tiny-home occupancy, minimum dwelling size or setbacks; ask Planning & Development about the exact parcel and use26.
- A state-highway driveway needs a signed and numbered LaDOTD access permit before construction, while a parish-road process was not confirmed23.
- Parish soils are overwhelmingly rated severely limited for conventional drain fields, so obtain a site-specific wastewater evaluation before relying on a parcel as buildable21.
Sources
- St. Tammany Parish Department of Permits and Inspections (2026 county census)
- Zoning Layer (2026 county census)
- Environmental Services, quoted and re-checked
- Homeowner / Builder Affidavit, quoted and re-checked
- Layer: Zoning, quoted and re-checked
- St. Tammany Parish Department of Planning & Development (stpgov.org)
- RS 33:4721 — Regulation of size and use of buildings (Louisiana statewide rule), quoted and re-checked
- Louisiana Administrative Code, Title 43, Part VI, §701 (Louisiana statewide rule), quoted and re-checked
- Louisiana Revised Statutes 40:1730.23 — Enforcement of building codes by municipalities and parishes (Louisiana statewide rule), quoted and re-checked
- St. Tammany Parish Department of Permits and Inspections (stpgov.org)
- St. Tammany Parish Permits and Inspections, quoted and re-checked
- La. R.S. 33:4780.40 — Regulation authorized (Louisiana statewide rule), quoted and re-checked
- RS 33:4721 — Regulation of size and use of buildings (Louisiana statewide rule), quoted and re-checked
- RS 33:4721 — Regulation of size and use of buildings (Louisiana statewide rule), quoted and re-checked
- RS 33:4721 — Regulation of size and use of buildings (Louisiana statewide rule), quoted and re-checked
- Environmental Services, quoted and re-checked
- Environmental Services, quoted and re-checked
- St. Tammany Parish Department of Environmental Services (stpgov.org)
- Louisiana Administrative Code Title 51, Part XIII, Public Health—Sanitary Code (Louisiana statewide rule), quoted and re-checked
- Louisiana Administrative Code Title 51, Part XIII, Public Health—Sanitary Code (Louisiana statewide rule), quoted and re-checked
- Share of soils without severe limits for a conventional septic drain field (USDA SSURGO): Bolthole Index county data
- Louisiana Office of State Parks Policy and Procedure Memorandum #6 — Reservation Changes and Refunds (Louisiana statewide rule), quoted and re-checked
- LaDOTD Access Connections Policy (Louisiana statewide rule), quoted and re-checked
- Louisiana Administrative Code Title 51, Part XIII, Public Health—Sanitary Code (Louisiana statewide rule), quoted and re-checked
- State of Louisiana No Rise Certification Guidance (Louisiana statewide rule), quoted and re-checked
- Effective property tax rate: Bolthole Index county data
- Median property tax bill: Bolthole Index county data
Written September 28, 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.