Grayson County building permits: Sherman, Denison, county land

Search for "Grayson County building permit" and you will learn the answer depends on which side of a city limit line your lot sits on. Inside Sherman or Denison you deal with a city building department. Outside, the county issues no house permit at all, and yet a new home on county land still passes through a county office three times. Here is the map for 2026, with McKinney and Durant at the edges for comparison.

Unincorporated Grayson County: no house permit, three required steps

Grayson County states plainly that it does not require building permits or issue certificates of occupancy for single-family homes. That is not the same as no rules. The county's Development Services office at 100 W. Houston Street in Sherman handles three things a rural build cannot skip, and they come in this order.

Step 1. The 911 address and driveway certificate

You apply online for a Development Certificate and stake the driveway where it will leave the county road. The precinct foreman decides whether a culvert is needed and inspects the finished drive, and the address is issued after that inspection. Under the county's right-of-way rules, driveway culverts run from 12 to 36 inches in diameter, and the applicant buys and installs the pipe.

Step 2. The septic permit

Every tract needs an on-site sewage facility permit, whatever its size, and the county's septic office will not accept an application without the 911 address from step 1. A licensed site evaluator or engineer does the soil work and design. Under the county's septic order, lots under 2.5 acres need an aerobic system, and minimum lot sizes run from 1 acre with public water to 1.5 acres on a private well, with smaller minimums where the entire system uses drip irrigation.

Step 3. Floodplain review

Where a parcel touches mapped floodplain on the county's September 2022 flood maps, a floodplain development permit is required, and a home's lowest floor must sit at least 2 feet above base flood elevation. Checking the map before you buy land is cheaper than learning it after the pad is built.

One exception to the no-permit rule: the county fire marshal permits new commercial and public buildings and apartment buildings of four or more units. A private barn is a different conversation than a shop that will host customers.

Sherman: register, then document the structure

Inside the city, Sherman Development Services runs permits through its Self Service Portal, launched in March 2025. Every contractor registers with the city, and electrical, mechanical, and plumbing firms also show their state licenses. The city adopted the 2021 family of ICC codes, with local amendments requiring an engineered shear wall plan and a form board survey for every new house and residential addition. The new-home checklist adds foundation plans, a Manual J load calculation, a REScheck energy report, and the impact fee.

Sherman's published list of required permits is worth reading before any project. It requires a permit for every new fence, a demolition permit for interior demolition during a remodel, a permit for accessory buildings larger than 100 square feet or on a permanent foundation, a roofing permit for any re-roof, and permits for water heater replacements and permanent backup generators. New commercial projects need site plan approval from the Planning and Zoning Commission before a building permit application is accepted.

Denison: newer codes and a homestead rule

Denison's Building Department on West Chestnut reviews plans and inspects, with permits, contractor registration, and inspection requests running through the MGO Connect portal. Denison has adopted the 2024 ICC codes and the 2026 National Electrical Code. A homeowner may pull a permit on their own house only if it carries a homestead exemption; otherwise the applicant registers as a general contractor. For additions and foundation repair, the city's permit information says the foundation must be engineered.

The edges of the map: ETJ, McKinney, and Durant

Many acreage lots around Sherman, Howe, and Van Alstyne sit in a city's extraterritorial jurisdiction. State law lets a city extend its subdivision and platting rules into the ETJ but bars it from regulating land use, building size, or density there, and since 2023 landowners can petition for release from an ETJ under Local Government Code 42.101 through 42.105.

South of the county line, McKinney adopted the 2024 ICC codes effective October 1, 2025, asks for a structural engineer's letter certifying every residential foundation plan, and requires a final drainage survey no more than 30 days old. In unincorporated Collin County, the county issues a development permit for any project that disturbs ground and requires third-party inspections on new homes.

Across the river, Durant's Community Development Department handles permits, inspections, 911 addressing, and floodplain questions. Oklahoma's statewide minimum codes moved to the 2024 IRC and IBC on September 14, 2026, and in unincorporated Bryan County the Oklahoma Department of Environmental Quality, not the county, authorizes new septic systems.

Which office is yours

• Inside Sherman or Denison city limits: the city building department, through its online portal.
• Unincorporated Grayson County: Development Services for the address, driveway, septic, and floodplain; the fire marshal for commercial buildings.
• In a city's ETJ: the city for platting, the county for everything above.
• Anywhere in Texas: state-licensed electricians and plumbers, whether or not a permit exists.

Our Sherman and Grayson County permit guide puts every office in one table, and the permit FAQ covers who should pull the permit. For rural lots, the site preparation service builds the county's culvert, pad, and drainage steps into one written scope. Call or text with your address or parcel number and we can tell you which office governs it, including acreage just outside Denison and Sherman where the answer changes from one side of the road to the other.