🚰 Septic System in Davidson County, Tennessee
A new or replacement onsite wastewater (septic) system — tank, drainfield, and often a local health-department permit. Here is the Davidson County, Tennessee picture: who issues the permit (county vs. city), the Tennessee rule at a glance, a modeled local cost estimate, and the official sources to verify before you build.
Septic System permit in Davidson County, Tennessee
The Tennessee rule for a septic system, with fee range, timeline, go / no-go, and the official source. Whether the county or your city issues it depends on incorporation status.
Exact permit fees are set by the local building department. WikEst shows the published or code-based range where one exists, linked to its official source — verify the final amount at the source before budgeting.
🚰 Septic System permit fee in Tennessee
Representative cities for Tennessee: Nashville, Memphis.
All 20 project fee ranges in Tennessee
Official-source ranges where published; “By local jurisdiction” means no flat fee is published and the amount is set case by case.
| Project | Permit? | Authority | Fee range | Go / no-go |
|---|---|---|---|---|
| 🏠 Accessory Dwelling Unit (ADU) | yes | city | Valuation-based; Nashville residential fee is $5.00 per $1,000 of valuation. | allowed |
| 🪵 Deck / Porch | conditional | city | Valuation-based; set by the issuing city/county. | allowed |
| 🧱 Fence / Wall | conditional | city | Often no building permit below local thresholds; historic-overlay lots differ. | allowed |
| 🛖 Shed / Outbuilding | conditional | city | Valuation-based when over the size threshold. | allowed |
| 🪜 Basement Finish | yes | city | Valuation-based; includes trade permits. | allowed |
| 🚗 Garage / Carport | conditional | city | Valuation-based when a permit is required. | allowed |
| ☀️ Rooftop Solar PV | yes | city | Building + electrical permits; fee set by city. | allowed |
| 🌡️ HVAC Replacement | yes | city | Mechanical permit; fee set by city. | allowed |
| 🍳 Kitchen Remodel | conditional | city | Valuation-based when structural/plumbing/electrical work is included. | allowed |
| 🛁 Bathroom Remodel | conditional | city | Valuation-based when plumbing is relocated. | allowed |
| 🏗️ Room Addition | yes | city | Valuation-based; includes trade permits. | allowed |
| 🪟 Window / Door Replacement | conditional | city | Usually no fee for in-kind swap; permit needed if opening is enlarged or under stricter local codes. | allowed |
| 🏘️ Roof Replacement | conditional | city | Often over-the-counter or exempt for same-decking re-roof. | allowed |
| 🅿️ Driveway / Parking Pad | conditional | city | Building permit often not required; curb-cut/right-of-way work is separate. | allowed |
| 🏊 Swimming Pool / Spa | yes | city | Valuation-based; includes barrier/fencing and electrical bonding review. | allowed |
| 🧱 Retaining Wall | conditional | city | Valuation-based when over the height threshold. | allowed |
| 💥 Demolition / Teardown | yes | city | Demolition permit fee set by the city/county building department; verify locally. | allowed |
| 🚰 Septic System | yes | county | Septic permit fees set by the local county health department; verify locally. | allowed |
| 🔌 EV Charger | conditional | city | Electrical permit fee set by the city; verify locally. | allowed |
| ⚡ Standby Generator | yes | city | Electrical (and often mechanical/gas) permit fee set by the city; verify locally. | allowed |
Tennessee rule at a glance
Metro Nashville Codes Department / Development Services (consolidated city-county government)
Nashville and Davidson County are a consolidated metropolitan government (Metro). Building permits for the entire county are issued by the Metro Nashville Codes Department / Development Services — there is no separate county-vs-city permit split.
Modeled cost estimate — septic system in Davidson County, Tennessee
Statewide typical total: $4,400–$26,400 · ≈ $10,560 / each
Modeled estimate. This band is the citable Tennessee statewide contractor cost range (industry estimate, retrieved 2026-08-23). A per-county cost-of-living index (U.S. Census Bureau ACS) was not refreshed in this build (retrieval date 2026-08-29), so this page shows the statewide baseline rather than a county-specific figure. Local labor and material markets commonly shift a specific bid ±15–25% from the statewide median (industry observation, HomeAdvisor / Fixr). Always collect 2–3 written quotes from licensed local contractors before committing.
Frequently asked questions
Does a septic system need a permit in Davidson County, Tennessee?
Davidson County follows Tennessee state permit law. Whether the project needs a permit, and the fee, depends on size and scope — see the Tennessee rule at a glance below, then confirm with Metro Nashville Codes Department / Development Services (consolidated city-county government).
Who issues the septic system permit in Davidson County — the county or my city?
The county issues permits for both unincorporated areas and incorporated cities. The permitting authority is Metro Nashville Codes Department / Development Services (consolidated city-county government).
How much does a septic system cost in Davidson County, Tennessee?
WikEst shows the citable Tennessee statewide contractor cost band below (industry estimate, retrieved 2026-08-23). A per-county cost-of-living index was not refreshed in this build (retrieval 2026-08-29); local labor and material markets commonly shift a specific bid ±15–25% from the statewide median. Collect 2–3 written quotes from licensed local contractors.
How do I apply for a septic system permit in Davidson County?
Start at the official portal for Metro Nashville Codes Department / Development Services (consolidated city-county government) (linked above). Most offices accept online submissions; have your plans, site information, and contractor details ready before applying.
🏛️ Who issues permits in Davidson County?
📊 Septic System in all Tennessee
Septic System in other states
Tennessee permit cheat-sheet
| Project | Permit? | Authority | Typical fee | Timeline | Go / No-Go | Key notes |
|---|---|---|---|---|---|---|
| 🏠 Accessory Dwelling Unit (ADU) | Permit required | city | Valuation-based; Nashville residential fee is $5.00 per $1,000 of valuation. | Nashville DADU review under Metro Code §17.16.250; varies by city. | Generally allowed | Nashville streamlined DADU rules in 2025 (removed alley-access requirement, raised size limits); owner-occupancy is required. Other cities follow state ADU allowances. Exempt: Nashville allows detached ADUs (DADUs) by right in most residential zones (Urban Services District). |
| 🪵 Deck / Porch | Conditional | city | Valuation-based; set by the issuing city/county. | Memphis OCCE ~5–10 business days for standard decks. | Generally allowed | Footing depth follows local frost line (shallow in Memphis, ~12 in Middle TN). Exempt: Decks ≤200 sq ft, ≤30 in above grade, not attached, not serving a required exit are exempt. |
| 🧱 Fence / Wall | Conditional | city | Often no building permit below local thresholds; historic-overlay lots differ. | Usually no building-permit review below threshold. | Generally allowed | Pool-enclosure fences must meet the 48 in barrier requirement. Exempt: Nashville: fences exempt except in Historic Overlay districts or over 7 ft; Memphis generally requires a permit for new fences. |
| 🛖 Shed / Outbuilding | Conditional | city | Valuation-based when over the size threshold. | Small sheds often exempt; larger sheds need plan review. | Generally allowed | Structures with plumbing, electrical, or gas, or used as living space, require a permit. Exempt: One-story detached sheds ≤200 sq ft are exempt under the TN Residential Code. |
| 🪜 Basement Finish | Permit required | city | Valuation-based; includes trade permits. | Standard plan review 2–4 weeks. | Generally allowed | Under the state program, unfinished-basement slabs do not require a slab inspection. Exempt: Cosmetic finishing (paint, flooring) is exempt. |
| 🚗 Garage / Carport | Conditional | city | Valuation-based when a permit is required. | New-structure plan review; varies by city. | Generally allowed | Converting a garage to habitable space requires a permit and code compliance. Exempt: State program exempts detached garages/sheds not used for living; local codes may differ. |
| ☀️ Rooftop Solar PV | Permit required | city | Building + electrical permits; fee set by city. | Varies; streamlined review common for standard residential PV. | Generally allowed | Net-metering and state incentives apply. Exempt: No size exemption for permanent rooftop PV. |
| 🌡️ HVAC Replacement | Permit required | city | Mechanical permit; fee set by city. | Trade permits often issued quickly. | Generally allowed | Equipment must meet the Tennessee Energy Code (2018 IECC + amendments). Exempt: No exemption for equipment replacement/installation. |
| 🍳 Kitchen Remodel | Conditional | city | Valuation-based when structural/plumbing/electrical work is included. | Standard review for permitted scopes. | Generally allowed | Full remodels pull separate plumbing/electrical/mechanical sub-permits. Exempt: Cabinet/countertop swap in the same layout is exempt. |
| 🛁 Bathroom Remodel | Conditional | city | Valuation-based when plumbing is relocated. | Standard review for permitted scopes. | Generally allowed | Ventilation to the exterior is required. Exempt: Fixture-for-fixture swap in place is often exempt. |
| 🏗️ Room Addition | Permit required | city | Valuation-based; includes trade permits. | Nashville standard residential review targets ~5 business days. | Generally allowed | The addition must meet code even though the existing home is not brought up to code. Exempt: State program: additions over 30 sq ft require a permit. |
| 🪟 Window / Door Replacement | Conditional | city | Usually no fee for in-kind swap; permit needed if opening is enlarged or under stricter local codes. | In-kind swaps typically need no review; Nashville requires a permit for window/door/exterior changes. | Generally allowed | Replacement products must meet energy-code U-factor when the code is triggered. Exempt: Same-size, in-kind replacement is generally exempt under the baseline code. |
| 🏘️ Roof Replacement | Conditional | city | Often over-the-counter or exempt for same-decking re-roof. | Nashville requires a permit for re-roofing; Memphis exempts re-roof where no decking is modified. | Generally allowed | Repairs not exceeding 33% of roof area are normal maintenance in Nashville. Exempt: Re-roof not changing decking/structure is often exempt (Memphis); Nashville requires a permit. |
| 🅿️ Driveway / Parking Pad | Conditional | city | Building permit often not required; curb-cut/right-of-way work is separate. | Right-of-way permits reviewed by the city/utility. | Generally allowed | A separate right-of-way permit is usually needed to cut the curb. Exempt: Sidewalks and driveways ≤30 in above grade are exempt (Memphis/OCCE exemption list). |
| 🏊 Swimming Pool / Spa | Permit required | city | Valuation-based; includes barrier/fencing and electrical bonding review. | Plan review varies; barrier inspection required. | Generally allowed | Tennessee requires a 48 in high barrier/fence around pools (Nashville and state standard). Exempt: Prefabricated pools <24 in deep and <5,000 gal may be exempt (Memphis/OCCE). |
| 🧱 Retaining Wall | Conditional | city | Valuation-based when over the height threshold. | Over-threshold walls need plan review. | Generally allowed | Walls in steep-slope or karst/expansive-soil areas may trigger soils review. Exempt: Walls ≤4 ft (Nashville) / ≤3 ft (Memphis) are exempt unless supporting a surcharge. |
| 💥 Demolition / Teardown | Permit required | city | Demolition permit fee set by the city/county building department; verify locally. | — | Generally allowed | A full teardown or major structural demolition requires a demolition (building) permit from the local building department under the Tennessee Residential Code. Structures built before 1978 may require an asbestos/lead-paint survey and abatement, and utility disconnects are typically required before teardown. Interior non-structural strip-out may be exempt. |
| 🚰 Septic System | Permit required | county | Septic permit fees set by the local county health department; verify locally. | — | Generally allowed | New or replacement onsite wastewater (septic / subsurface sewage disposal) systems require a construction permit from the local county health department under Tennessee Code Annotated Title 68 (TDEC Ground Water Protection Program). A site/soil evaluation and engineered design are typically required; new subdivisions need health-department approval before any septic permit. |
| 🔌 EV Charger | Conditional | city | Electrical permit fee set by the city; verify locally. | — | Generally allowed | A home EV charging station normally requires an electrical permit for a dedicated 240V circuit and wall unit, issued by the city under the Tennessee Residential Code / NEC. Plug-in (cord-and-plug) Level 1 charging from an existing outlet may be exempt where code allows; a new dedicated circuit or hardwired unit requires a permit. |
| ⚡ Standby Generator | Permit required | city | Electrical (and often mechanical/gas) permit fee set by the city; verify locally. | — | Generally allowed | A permanently installed standby generator with a transfer switch and fuel (natural gas/propane) line requires electrical and often mechanical/gas permits, plus inspection (NEC Art. 445/702 context). Setback, noise, and carbon-monoxide rules may apply, and HOAs may restrict installation. Verify with the city building department. |