Missouri assesses residential real property at 19% of true value, agricultural at 12%, and all other real property at 32% (RSMo 137.115). A barndominium's living area is residential. The shop is residential too — unless the land is classified agricultural and the shop is actually used for farming, in which case the assessor allocates that portion to the agricultural class by use (RSMo 137.016.4). A farm dwelling and up to five acres around it are residential no matter what. That is the whole framework; the rest is how your county assessor applies it.
Missouri property tax classifications
RSMo 137.016.1 defines the three classes:
- Residential: "all real property improved by a structure which is used or intended to be used for residential living by human occupants," along with vacant land in residential zoning and some other categories. Assessed at 19%.
- Agricultural and horticultural: land "actually used for agricultural purposes" and "buildings and structures customarily associated with farming, agricultural, and horticultural uses." Assessed at 12% (and ag land is valued on a productivity grading, not market).
- Utility, industrial, commercial, railroad and other: everything else, at 32%.
How the home, shop and land are classified
| Part of the property | Class | Why |
|---|---|---|
| Living area | Residential, 19% | A structure used for residential living |
| Shop used as a garage, hobby shop, storage | Residential, 19% | Part of the residence; not a farm structure |
| Shop used for a business (contractor, mechanic, retail) | Commercial, 32%, for that portion if the assessor allocates it | "Other" use |
| Shop used for farming, on land classified agricultural | Agricultural, 12%, for that portion | A structure "customarily associated with farming" — but only if the farming is real |
| The house and up to 5 acres on a farm | Residential, 19% | 137.016.4 specifically |
| Remaining acreage in agricultural use | Agricultural, 12%, productivity-valued | — |
The split-classification rule (137.016.4) tells the assessor to "allocate to each classification the percentage of the true value in money" by the use of each part. In practice that means the assessor asks what the shop is for. A three-bay shop with a truck, a lawn mower and a workbench is residential. A grain-storage bay on a parcel with a crop lease may be agricultural. A shop with a sign out front and customers is commercial.
What the assessor will do
New construction is picked up at the next assessment cycle from the permit (in Franklin, Jefferson and St. Charles) or from the structure permit and the field (in Warren, where there is no building permit, and Lincoln, where there is none at all). You will get a notice of value; you can appeal to the Board of Equalization. Counties reassess in odd-numbered years. A new barndominium on rural land typically shifts the parcel from agricultural (12%, productivity-valued) to a residential improvement plus a residential homesite (the house and up to five acres at 19%, market-valued), with any remaining farmed acreage staying agricultural.
Why it matters when you design
- If part of the appeal of a barndominium is a big shop, know that a residential shop is taxed at 19% of its market value like the rest of the house. It does not get the 12% rate because it looks like a barn.
- If you farm the land — a hay lease, cattle, a crop — the ag classification on the acreage beyond the homesite is a real saving, and the shop portion used for that farming can follow it. Document the use.
- A business in the shop has tax consequences beyond property tax (zoning home-occupation rules, insurance, sales tax) — see shop-houses.
Frequently asked questions
Can I get the whole barndominium assessed as agricultural? No. The dwelling and its five acres are residential by statute.
Does calling it a "barn" on the permit change the tax? No, and calling a dwelling a barn on a permit creates problems with the county, the lender and the insurer that are worse than the tax.
Is the land valued at market or productivity? Agricultural land is valued by a productivity grade set by the State Tax Commission; the residential homesite is valued at market.
Who do I ask? The county assessor's office in Union, Hillsboro, Warrenton, Troy or St. Charles.
Next step
Shop-houses and custom barndominiums. Related: land, septic and well · the complete guide.