ADU (Accessory Dwelling Unit) permit in Nashville, TN
Yes — you need a permit for adu (accessory dwelling unit) work in Nashville.
Building a detached accessory dwelling unit (DADU) is construction of a new structure that creates new floor area, so it needs both a zoning permit and a building permit. A zoning permit must be filed before any construction of a structure begins, and no building permit is issued without a valid zoning permit. Inside a DADU overlay the unit is a permitted land use subject to the overlay's standards.
| Permit needed? | Yes |
|---|---|
| Where the line falls | Building a detached accessory dwelling unit (DADU) is con… |
| Fee | Residential building permit fee is $5.00 per $1,000 of total valuation (16.28.110.A.1). |
| Review time | Not in the ordinance |
| Code section | 17.40.520 (zoning permit required before construction; building permit issued only on a valid zoning permit); DADU standards in 17.36.710 / 17.36.730 |
| Based on | 2024 IRC for One- and Two-Family Dwellings as amended; Metro Zoning Code Title 17 |
How to pull the permit
- Put together a site plan showing where the work goes, with dimensions.
- Apply through the Nashville building department.
- Pay the permit fee when the permit is issued. Work done before that isn't covered.
- Book each inspection listed on the permit as the job reaches that stage.
Either of you can pull it. When a contractor does the work, it is normally their job.
If you skip it
Nashville's code doesn't set a specific fine for this work. In practice the department can issue a stop-work order, and unpermitted work tends to surface during a sale, when the buyer's inspector or the title company asks for it.
Nearby cities, same job
Rules stop at the city line. If your lot is near a boundary, or you work across several towns, this is where they differ.
| City | Distance | Permit? | Where the line falls |
|---|---|---|---|
| Nashville | — | Yes | Building a detached accessory dwelling unit (DADU) is con… |
| Goodlettsville | 12 mi | Yes | No size threshold in the code |
| Brentwood | 12 mi | Yes | No size threshold in the code |
| Hendersonville | 14 mi | Yes | No size threshold in the code |
| Mount Juliet | 15 mi | Yes | No size threshold in the code |
| Nolensville | 16 mi | Yes | No size threshold in the code |
See every Tennessee city on adu (accessory dwelling unit) work
Other work in Nashville
Questions people ask
How much does a adu (accessory dwelling unit) permit cost in Nashville?
Residential building permit fee is $5.00 per $1,000 of total valuation (16.28.110.A.1).. Valuation-based fees mean the number depends on what the job is worth, so the department quotes it when you apply.
I already built it without a permit. What now?
Nashville can issue a stop-work order and require you to apply after the fact, sometimes with an extra fee. Work that was covered up may have to be opened for inspection. Full walkthrough here.
Does unpermitted work cause problems when selling the house?
Often, yes. A buyer's inspector or the title company may flag it, and lenders can balk at financing a home with open or missing permits. What to do about it.