How the bill is worked out
- The assessor appraises the land and buildings at market value.
- That value is multiplied by the class rate: 10% for owner-occupied homes, farmland and timberland, 20% for other property such as a rental or a second home (Alabama Department of Revenue).
- The assessed value is multiplied by the millage for your tax district (one mill is $1 per $1,000).
- Exemptions come off the top. In Madison County, the assessor's own example shows the standard homestead exemption saving about $48 (Madison County Tax Assessor).
Millage by place, with a worked example
| Where the barndo sits | Total mills | Tax on $400,000 (before homestead) |
|---|---|---|
| Madison County, outside any city | 36.5 | $1,460 |
| Owens Cross Roads, Gurley, New Hope | 40.5 | $1,620 |
| City of Huntsville (Madison County side) | 58 | $2,320 |
| Town of Triana | 61.5 | $2,460 |
| City of Madison (Madison County side) | 69.5 | $2,780 |
| Limestone County, outside any town | 30 | $1,200 |
| Lester, Mooresville | 35 | $1,400 |
| Athens, Ardmore, Elkmont | 40 | $1,600 |
| Huntsville (Limestone County side) | 55 | $2,200 |
| Madison (Limestone County side) | 72 | $2,880 |
Our math: $400,000 × 10% × mills ÷ 1,000. Rates from the Madison County Tax Collector and the Limestone County Revenue Commissioner, read November 2026. Rural Madison County land with no buildings pays 33.5 mills; the extra 3 mills for volunteer fire apply to improvements. A barndo that isn't your main home is assessed at 20%, which doubles these figures.
Homestead and over-65 exemptions
If the barndo is your main home on October 1, the standard homestead exemption takes $4,000 of assessed value off the state tax and $2,000 off the county tax (Alabama DOR). Limestone County applies the same limits, excluding school and city taxes (Limestone Revenue Commission). Owners 65 and over pay no state property tax, and those with net taxable income of $12,000 or less pay none at all (Alabama DOR). Apply at the assessor's office by December 31.
Timing for a new build
Alabama assesses property as it stood on October 1. Report new improvements to the assessor; Madison County can add a 10% penalty to an improvement nobody reported (Madison County Tax Assessor). So whatever stands on October 1 is what is assessed for that year, including a barndo that is only half built. Ask the assessor how they value work in progress, and ask your lender how taxes are escrowed during the build.
Acreage and current use
Many barndos sit on farm or timber land. Alabama's current use program lets qualifying farm, pasture and timber land be valued at its current use instead of its market value. In Madison County you apply between October 1 and December 31, and if the land later changes use, a rollback tax can be due (Madison County); in Limestone the deadline is December 31 before the tax year (Limestone County).
Appraisal, shops and appeals
The county appraiser values your barndo from sales and building data, much like a lender's appraiser does (see loans and appraisals). We couldn't find a published rule on how a shop bay under the same roof is classed, so ask the assessor before you finish plans. If a value looks high, call the office before the deadline on your notice. Madison County Tax Assessor: 256-532-3350. Limestone County Revenue Commission: 256-233-6433. Rules on where you can build are on our zoning and permits page.
Common questions
How much are property taxes on a barndominium in Madison County?
Outside city limits, 36.5 mills on 10% of value for an owner-occupied home: about $1,460 a year on $400,000 before the roughly $48 homestead saving (Madison County). Inside Huntsville it is 58 mills.
Are property taxes lower in Limestone County?
Outside the towns, yes: 30 mills, against 36.5 in rural Madison County. Inside Athens it is 40, and the Huntsville and Madison parts of Limestone run 55 and 72 (Limestone Revenue Commissioner).
Is a barndo taxed differently from a regular house?
Not by class: an owner-occupied barndo is Class III residential at 10%, like any home (Alabama DOR). Its appraised value depends on size, finish and local sales.
When does a new barndo start being taxed?
Alabama assesses property as of October 1 each year, and new improvements must be reported to the assessor (Madison County Tax Assessor).
Sources & further reading
- Alabama Department of Revenue: property (ad valorem) tax classes
- Alabama Department of Revenue: homestead exemptions
- Madison County Tax Assessor: property tax facts (read Nov 2026). Oct 1 status date, penalties, homestead example, current use
- Madison County Tax Collector: millage rates (read Nov 2026)
- Limestone County Revenue Commissioner: millage rates (read Nov 2026)
- Limestone County Revenue Commissioner: assessment information (2025). Homestead, current use deadline
Editorial note: General planning information, not engineering or legal advice. Prices are estimates; confirm current rules with your local officials and a qualified pro.