Barndominiums in Tennessee: Can You Build One in Williamson or Maury County?

Quick answer (as of November 2026) Yes, you can build a barndominium in Williamson County and Maury County, Tennessee. Neither county's zoning ordinance has a separate barndominium category, so a barndominium you live in is permitted as a single-family home: it has to meet the zoning district's lot size and road frontage, get a septic permit and pass the county's residential building code. In unincorporated Williamson County, the RP-5 and RD-5 rural districts need 5 acres for a traditional lot. In unincorporated Maury County, the RR district needs 5 acres and 200 feet of public road frontage, and RG needs 1 acre. Inside a city like Franklin, Spring Hill or Columbia, the city's rules apply instead.

Send me the moving guide

You found 10 acres outside Franklin or Columbia, you've already picked a barndominium floor plan, and the listing says "no restrictions." Whether that plan works comes down to three things the listing won't tell you: the zoning district, the soil, and whether a lender will finance a house an appraiser has to compare with ordinary homes.

I work with land buyers across Williamson and Maury County, and I've been investing in real estate since 2005. On every tract, I check the county, the zoning district, the road frontage and the septic answer before you're under contract. Send me the listing or the parcel and I'll run those checks with you. DM me, text or call 615-392-1186.

What counts as a barndominium in Tennessee?

A barndominium is a house built like a barn: usually a metal or post-frame shell, an open floor plan and often a shop or garage under the same roof. Williamson and Maury County don't define the word in their zoning ordinances, so the county looks at how the building is used.

Williamson County's zoning ordinance calls any building with its own kitchen, sleeping area and full bathroom a dwelling. Once your barn has those three things, it's a house in the county's eyes, and it needs a zoning certificate and a building permit like any other house.

Can you build a barndominium in Williamson County?

Yes. Williamson County's zoning ordinance doesn't single out barndominiums or ban metal siding on a home, so a barndominium in unincorporated Williamson County follows the same rules as any single-family home in its district. That's the ordinance in effect since January 1, 2013, with amendments listed through January 12, 2026.

Here's what the county's rural districts require for a home:

District standards from the Williamson County Zoning Ordinance, as of November 2026. Look up your parcel's district on the county's Official Zoning Map.

Every lot also has to front a public road for at least its district's minimum lot width, with a narrow exception for lots that share a platted access easement. Some village districts add rules for how wide a building's front can be compared with its neighbors, so if your parcel sits in a village district, read that district's standards before you pick a plan.

The county won't issue a building permit until the zoning certificate is approved and the water, septic, storm water and driveway approvals are in hand. Williamson County enforces the 2021 International Residential Code. The Building Codes department is at 1320 West Main Street, Suite 400, in Franklin, (615) 790-5718, and zoning questions go to Community Development at (615) 790-5725. Electrical permits in the unincorporated county come from the State of Tennessee.

The county's process covers unincorporated Williamson County. If your land is inside Franklin, Brentwood, Fairview, Nolensville, Spring Hill or Thompson's Station, that city handles zoning and permits.

Can you build a barndominium in Maury County?

Yes. A single-family detached home is a permitted use in Maury County's AP, RR and RG districts. The RR district needs 5 acres and 200 feet of public road frontage, and RG needs 1 acre and 100 feet.

Maury County's zoning ordinance (effective January 1, 2026, revised through July 20, 2026) applies to unincorporated Maury County and has no barndominium category. Its design standards cover multifamily, townhouse and big retail buildings, and none of them apply to a single-family home.

District standards from the Maury County Zoning Ordinance, as of November 2026. In RR and RG, two homes on one lot can share one building with a fire wall or sit in two buildings at least 40 feet apart.

Maury County enforces the 2018 International Residential Code, with the 2009 insulation tables swapped in by a 2020 amendment. The county's 2026 permit packet says to bring these to the Building and Zoning Office at 5 Public Square in Columbia (931-375-3002):

1. A septic permit from TDEC's office at 1421 Hampshire Pike in Columbia (931-380-3371).
2. Proof of a water tap or water source for each home.
3. Driveway approval from the Maury County Highway Department on a county road, or from TDOT on a state road.
4. House plans drawn to scale, including a foundation plan, a floor plan and elevations.
5. A plot plan showing the distances to every property line.
6. A copy of the deed if you're building it yourself as owner, or proof of a Tennessee contractor's license and a Maury County business license for your builder.

If you're splitting a lot of less than 5 acres off a larger tract, the packet says a minor plat has to be approved and recorded before the county will issue a home permit for it. Inside Columbia, Spring Hill or another city, the city's rules apply instead of the county's.

How do Williamson, Maury and Davidson County compare for a barndominium?

All three treat a barndominium you live in as a house. The differences are in who approves the septic, which code edition applies and how much land you need.

How many acres you need depends on the county and the zoning district. In unincorporated Williamson County, the RP-5 and RD-5 rural districts need 5 acres for a traditional lot, and RP-1 and RD-1 need 1 acre. In unincorporated Maury County, AP needs 15 acres, RR 5 acres and RG 1 acre.

As of November 2026, from each county's ordinances, permit pages and TDEC's septic contacts list.

What about a barndominium in Nashville or Davidson County?

In Davidson County, Metro Nashville's zoning code applies. Metro Planning describes its two agricultural districts this way: AG needs a 5-acre minimum lot and AR2a a 2-acre minimum, and single-family homes are allowed in both. Metro adopted the 2024 International Codes in July 2025. TDEC lists Davidson as a contract county, so septic permits run through Metro's health department. Check the parcel's zoning with Metro before you buy.

What septic and soil rules apply to a rural lot for a barndominium?

On a rural lot, the septic permit can decide where the house goes and how big it can be, so get the answer before you commit to the land. TDEC says to get the septic permit before any dirt work and before building, including the house pad.

Who issues it depends on the county:

1. Williamson County runs its own program. TDEC lists it as a contract county, and the county's subdivision regulations say every septic system has to be approved by the Department of Sewage Disposal Management. A lot served only by septic needs whichever is larger, the zoning minimum or the septic regulations' minimum, and the system has to sit on the lot it serves.
2. Maury County septic permits come from TDEC's Columbia office, and the county won't take a home permit application without one. The plot plan has to note that the septic system sits on the lot it serves, not in an easement on another lot.
3. Davidson County is also a contract county, run through Metro's health department.

If the soil won't take a conventional system, an alternative system needs an extra-high intensity soils map drawn by a soils consultant licensed in Tennessee before TDEC will evaluate it. On a tract you love, make the offer contingent on the septic approval for the house size you want.

Can you put living quarters in a shop or barn building?

You can, with a permit and within each county's accessory dwelling rules. Williamson County requires a building permit before any conversion of a building, and adding a kitchen, sleeping area and full bath turns a shop into a dwelling under the county's definition. Here's how the two counties size an apartment that sits with a main house:

From each county's zoning ordinance, as of November 2026.

Big shops have their own limit in Maury County. On a lot over 1 acre, no single accessory building can be larger than 75 percent of the house or 2,000 square feet, whichever is greater. On a lot over 5 acres, it can be bigger if it sits at least 200 feet back from the front property line. And in Maury's RR district, a 5-acre lot can carry two principal homes, which is another way to put a barndominium and a second house on the same land.

Can you get a mortgage on a barndominium?

It can be, once the house is finished. A construction-to-permanent loan pays for the build and then converts to a long-term mortgage, and the lender will want a certificate of occupancy before it does. Ask each lender which terms, including 30 years, it offers on a barndominium.

Fannie Mae's Selling Guide, which many lenders follow, allows these loans with one closing or two. Under its single-closing rules, as of November 2026:

1. No single construction period can run over 12 months, and the total can't run over 18 months.
2. The loan-to-value is figured on the "as completed" value of the lot and the house.
3. Fannie Mae can't buy the loan until construction is finished and it has converted to permanent financing.
4. The lender keeps a completion report and, for a loan that covers the lot and the construction, a certificate of occupancy.

The harder part is the appraisal. Fannie Mae requires at least three closed comparable sales, and says sales from the last 12 months should be used. Where there's a shortage of truly comparable sales, the appraiser can use other sales if the analysis is documented and explained. Out in rural Maury or southern Williamson County, there may not be three recent barndominium sales nearby, so the appraiser may lean on ordinary homes, and that can come in under your budget.

Before you buy the land, talk to a lender who has closed a barndominium construction loan and ask how their appraiser handles comparables.

How is a barndominium taxed in Tennessee?

Tennessee taxes a barndominium you live in as residential property. The state classifies property by its current use, and residential real property is assessed at 25 percent of its appraised value, the same rate as farm real property. The county assessor sets the appraised value.

New construction reaches the tax rolls through the assessor. Williamson County's assessor tracks building permits and completion notices to capture new homes and additions. Maury County's assessor values a property at market value as of January 1 of the last reappraisal year, plus the equalized value of improvements added since. Maury reappraises every four years, and 2026 is the current reappraisal year.

Both counties also charge on new living space when you pull the permit. In unincorporated Maury County, the New Development Tax is $1.50 per square foot of heated and cooled residential space (effective November 1, 2024), paid by a separate check from the permit fee. Williamson County's permit fee schedule lists a privilege tax on new living space; get the current amount from the Building Codes department.

If the land is in greenbelt, building on it can change that. My guide to buying land in College Grove covers greenbelt rollback taxes and who pays them.

Property tax figures are the county and city rates published for the year shown and are for planning only. Your actual bill depends on the assessed value, any exemptions and the city or district the home sits in. Confirm with the county assessor or trustee and your tax professional before you rely on a number.

Do HOA rules or deed restrictions block barndominiums?

They can. Zoning and recorded restrictions are separate things, so check the recorded documents before you buy. A tract in a subdivision, or one split from a larger farm, can carry recorded restrictions or HOA rules on exterior materials, minimum house size, outbuildings or animals.

Ask for three things during your due diligence:

1. The recorded restrictions and any HOA documents for the tract.
2. The recorded plat, including its notes, setbacks and easements.
3. The title commitment, which lists the recorded restrictions on the tract, before closing.

If anything mentions exterior materials or metal buildings, have a real estate attorney read it before your due diligence period ends. This is general information, not legal advice.

How do you choose a barndominium builder in Tennessee?

Start with the license. Maury County requires proof of a valid Tennessee contractor's license and a county business license before it issues a permit to a contractor, and you can check any builder's license on the state's license lookup.

Then ask every builder the same questions:

1. Have you built and finished a barndominium in this county, and passed final inspection?
2. Does your bid include the site work, driveway, septic system and utility connections, or only the building?
3. Who pulls the permits, and who's responsible for the plans meeting the county's residential code?
4. Has a lender's appraiser valued one of your finished barndominiums, and what comparables did they use?

Get the answers in writing, and get your septic permit before you sign a building contract.

What should you check before you buy land for a barndominium?

1. Which county the land is in, and whether it's inside a city.
2. The zoning district, its minimum lot size and its road frontage rule.
3. The septic answer for the house size you want, or an offer contingent on it.
4. Water at the road, and who provides it.
5. Driveway approval from the county highway department or TDOT.
6. The flood map for the house site.
7. Recorded restrictions, HOA rules and greenbelt status.
8. A lender who'll finance the build, and how their appraiser handles comparables.

To start looking, see my land pages for Franklin, College Grove, Spring Hill, Columbia and Maury County. If you're moving from out of state, start with moving to Tennessee.

Can't get here to walk the land? I'll record a video walkthrough of the tract and send you an unlisted YouTube link, so you can rewatch it as often as you want and show it to anyone in the decision. Here's how I work with out-of-state buyers.

The full checklist, from land loans to greenbelt rollback taxes, is in my guide to buying land in Tennessee.

Frequently asked questions

Can you build a barndominium in Williamson County, TN?

Yes. Williamson County's zoning ordinance doesn't single out barndominiums or ban metal siding on a home, so a barndominium in unincorporated Williamson County follows the same rules as any single-family home in its district.

Can you build a barndominium in Maury County, TN?

Yes. A single-family detached home is a permitted use in Maury County's AP, RR and RG districts. The RR district needs 5 acres and 200 feet of public road frontage, and RG needs 1 acre and 100 feet.

How many acres do you need for a barndominium in Tennessee?

It depends on the county and the zoning district. In unincorporated Williamson County, the RP-5 and RD-5 rural districts need 5 acres for a traditional lot, and RP-1 and RD-1 need 1 acre. In unincorporated Maury County, AP needs 15 acres, RR 5 acres and RG 1 acre.

Can you get a 30-year mortgage on a barndominium?

It can be, once the house is finished. A construction-to-permanent loan pays for the build and then converts to a long-term mortgage, and the lender will want a certificate of occupancy before it does. Ask each lender which terms, including 30 years, it offers on a barndominium.

How is a barndominium taxed in Tennessee?

Tennessee taxes a barndominium you live in as residential property. The state classifies property by its current use, and residential real property is assessed at 25 percent of its appraised value, the same rate as farm real property.

Do I need a septic permit before I build a barndominium?

Yes. TDEC says to get the septic permit before any dirt work and before building, including the house pad. In Williamson County, the county's Department of Sewage Disposal Management approves septic systems; in Maury County, the permit comes from TDEC's Columbia office.

Where can you see barndominiums for sale in Middle Tennessee?

I keep a live search of the MLS listings that mention a barndominium: see barndominiums for sale. It matches the word in the listing, so some results are land where one could go or a house with a barndominium-style shop on the lot. Read each one, then text me the ones you like and I'll pull the county rules for that tract.

Want a second set of eyes on a tract?

Send me the listing or the parcel number, and I'll check the county, the zoning district, the road frontage and the septic path with you before you make an offer. DM me, text or call 615-392-1186.