Buying land here? Start with the plat.

No, and this is the most expensive wrong assumption in this market. Buildability in Grayson County runs through the recorded plat. The county's subdivision regulations list eight exceptions to platting, and two of them, the phased-subdivision exemption and the agricultural-use exemption, say in so many words that properties subdividing under them are not eligible for an E911 address or an on-site sewage facility permit. No address means the county will not even accept a septic application, and no septic permit means no house. The tract is not ruined, it is just not buildable until it goes through proper platting. Other exemptions do not carry that disability, so the answer depends entirely on which exemption a tract was split under. That is a records question, and it is the first one I answer.

Because full subdivision approval costs real money and takes real time, and the exemption route avoids both. A seller who wants to break a larger property into sellable pieces can do it under the phased or agricultural-use exemption quickly and cheaply, and the tracts that result are legally created and can be legally sold. That is usually not a scheme, it is just the cheapest path to a sale, and the seller may genuinely not know what it costs the buyer. The problem lands on whoever buys expecting to build. Ask the county for a written Formal Determination of Exemption Status before you write the offer, and you will know which situation you are in.

Yes. Grayson County requires an application, permit, authorization to construct and inspection for an on-site sewage facility regardless of the size of the tract. The county adopted that rule deliberately as a stricter local standard, and a stricter local rule takes precedence over the corresponding state requirement. That matters because Texas has a state-level exemption for single-family tracts of ten acres and up, and people arrive expecting it to apply here. In Grayson County it does not.

On any parcel under 2.5 acres, yes. The county order requires an aerobic treatment process for any on-site sewage facility on a tract smaller than 2.5 acres. Two things to get right about that rule, because they are widely misreported. It is a Grayson County rule rather than a state one, and it is a pure lot-size test, so it has nothing to do with whether you are on public water or a well. Aerobic systems cost more to install and carry an ongoing maintenance contract, so it belongs in your budget from the start. Water supply type does matter, but for a separate rule: it drives the minimum lot size the county will allow for a septic system at all.

It depends on your water source and your system type. Without a public water source the minimum is 1.5 acres, or 1 acre if the system uses subsurface drip irrigation. With a public water source it is 1 acre, or half an acre with subsurface drip. Non-residential uses have a higher floor and do not get the drip discount. Watch the interaction between the two rules: a 1-acre lot on public water clears the minimum lot size, but because it is still under 2.5 acres it will require an aerobic system.

If a public sewage system is within 100 feet of the property, yes, use of it is required. There is a clause worth knowing, though: the requirement can be waived with written approval from the County Engineer. Most summaries of this rule leave that part out and make it sound absolute.

Generally 10 acres, but that number carries two qualifiers. First, the appraisal district sets minimums by agricultural use rather than one blanket number, and most of those uses come out at 10 acres, though not all of them do. Second, and this is the part people miss, the district states plainly that its guidelines are a general guide and that exceptions are handled case by case by the Chief Appraiser. So 10 acres is the planning number, not a wall. The requirement that catches more buyers is the history: the district generally wants proof of qualifying agricultural use in five of the seven preceding years. Ag valuation does not automatically arrive with your deed.

Between 5 and 20 acres. That range is set by state statute rather than by the county, so it is the same everywhere in Texas. Grayson County then sets the intensity standard on top of it: a minimum of six hives on the first 5 acres, plus one additional hive for each additional 2.5 acres, which works out to somewhere between six and twelve hives across the qualifying range. The hives have to be maintained and kept alive. One point in your favor: the district applies the productivity appraisal to the total acreage, not only the ground the hives sit on.

A rollback is the back-tax bill that comes due when land in agricultural valuation changes to a non-agricultural use. The county recaptures the difference between the ag-value tax and the full market-value tax for the three years before the change. There is no interest. House Bill 3833 removed the interest provision effective June 15, 2021. This is worth checking your sources on, because Grayson CAD's own agricultural guidelines, in the current April 2025 revision, still print the repealed five percent interest. The statute controls. If a number you were quoted came off a county handout, check the date on the handout.

It is a utility's written certification that it can actually serve a development, and Grayson County requires one from the water, sewer, electric and natural gas providers when you subdivide. The operative language is that the provider certifies existing capacity with an effective date of service. That date is the chokepoint. A supplier that will not commit to when service starts can stop a plat, which is why availability is a question to settle in writing early rather than assume from a map. If a subdivision proposes individual wells, the county may also require a professional engineer's report certifying adequate groundwater.

No. State law is explicit that a division counts regardless of the method used, whether that is a metes and bounds description in a deed, a contract for deed, a contract of sale, or any other method. Dividing a tract outside city limits into two or more parts to lay out a subdivision or lots triggers the platting requirement on its own terms. The deed language does not change what happened to the land.

The right agent for county land is one who works the records rather than the listing photos, because out here the things that decide value are not visible on a walk-through. Whether a tract carries a recorded plat or was split under an exemption that blocks an address and a septic permit. Whether the soil will take a system, and which system the lot size forces. Which water supplier holds the certificate for that parcel and whether they will commit to a meter in writing. What the ag valuation does on closing and what a rollback would actually cost now that the interest is gone. That is the work Nychole Baxter does across Grayson, Fannin, Collin, Hunt and Cooke counties, as someone who owns land and runs cattle rather than someone reading about it. She is a REALTOR®, not an engineer, surveyor or tax advisor, so she brings in the site evaluator, the surveyor and the tax professional a deal needs and makes sure the questions get asked before the offer. The way to judge that is a conversation about the specific tract you are looking at.