County permitting reference
Building a barndominium or barn in Kendall County: permitting and site work
Kendall County covers Boerne and Comfort, the fastest-growing edge of the Hill Country as San Antonio pushes north. The county uses a development-permit system rather than a building code, and it holds the one genuine Edwards Aquifer wrinkle in our whole service area, down in the southeast corner near Boerne.
Does Kendall County require a building permit?
Kendall County does not enforce a general building code in the unincorporated county. Instead it runs a development-permit process that covers septic, rural addressing and access, floodplain, and subdivision platting. The City of Boerne runs its own building permits inside the city and its ETJ. For most rural Kendall County projects, the septic permit and the development permit are the steps that matter, not a building inspection.
Septic (OSSF) is the step that governs
The on-site sewage facility permit, the septic permit, is usually the binding approval for a rural Hill Country build. In Kendall County it runs through the Kendall County Environmental Health. Located on East San Antonio Avenue in Boerne. Confirm the current phone, email, and the development-permit checklist on the county Onsite Sewage page. Ignore any out-of-state phone result: Kendall County, Illinois shares the name.
Local detail: Kendall County Environmental Health is the local OSSF authority. The septic permit is part of the county development-permit process, so it is usually handled alongside addressing and access. If your parcel is in the southeast of the county near Boerne, read the Edwards Aquifer note below before you design, because the rules can change for those specific parcels.
Visit the official Kendall County page to confirm current forms, fees, and contacts.
The 10-acre septic exemption
Kendall County follows the statewide 30 TAC 285.3 rule. A single-family home on 10 or more acres can be exempt from the septic permit when every part of the system is at least 100 feet from the property lines, effluent stays on the tract, and it is the only dwelling on the tract. As everywhere in the Hill Country, the exemption removes the permit step but not the construction standards, and karst limestone usually pushes you to an aerobic treatment unit. Confirm any exemption with county Environmental Health before relying on it.
Edwards Aquifer
This is the one real Edwards Aquifer case in our area. Kendall County is not on TCEQ's list of regulated Edwards Aquifer Protection Program counties, but the boundary of the regulated recharge zone literally begins inside Kendall County at Herff Falls on Cibolo Creek, in the southeast near Boerne. Parcels in that southeast corner can fall in mapped recharge or contributing zone, which can trigger a Water Pollution Abatement Plan or Contributing Zone Plan and a longer TCEQ review. If your land is anywhere near Cibolo Creek or the Boerne side of the county, check the TCEQ Edwards map viewer for your exact parcel before you design. Most of the county is clear, but that corner is not.
Wind load and exposed sites
The Hill Country sits in the roughly 105 to 115 mph design wind speed band (3-second gust, Risk Category II) under ASCE 7-16, the standard most Texas building codes reference. Most parcels fall between mapped contours, so a designer pulls the exact value for your address from the ASCE Hazard Tool. The local twist is the topographic factor, Kzt: an exposed ridge, hilltop, or escarpment raises the effective wind pressure on a building, sometimes by half again versus flat open ground. A metal or post-frame building on a Hill Country ridge should be engineered for that, which is one reason a sealed design from the builder matters here.
Wells and groundwater
Boerne and Comfort sit on Hill Country limestone, so wells can be deep and water planning matters. Confirm groundwater district registration for any new well, and remember that a well budget and a septic budget both belong in your numbers from the start.
Ag valuation and your buildings
A 1-d-1 open-space valuation from the Kendall Appraisal District lowers the tax valuation on qualifying land, not on buildings. A barn, shop, or barndominium is appraised separately at market value. There is no county square-footage threshold that makes a building permit-free, and ag valuation does not remove the septic or development permit. Ask the appraisal district directly about any structure tied to a qualifying ag operation.
Sources and where to verify
Kendall County permitting questions
Do I need a permit to build a barndominium in Kendall County?
In the unincorporated county there is no general building code, but Kendall County runs a development-permit process that includes the septic permit, addressing, and access. You handle those with county Environmental Health. Inside the City of Boerne and its ETJ, city building permits apply.
Is my land near Boerne in the Edwards Aquifer recharge zone?
It can be. The regulated Edwards recharge zone begins inside southeast Kendall County at Herff Falls on Cibolo Creek, near Boerne. Parcels in that corner may fall in mapped recharge or contributing zone and trigger a TCEQ Water Pollution Abatement Plan. Check the TCEQ Edwards map viewer for your exact parcel. Most of the county is outside the regulated zone.
Do I need a septic permit on 10 acres in Kendall County?
Maybe not, if you meet the statewide 10-acre exemption: a single-family home that is the only dwelling on the tract, with the system at least 100 feet from property lines and effluent kept on the property. The system still must meet state construction standards. Confirm with Kendall County Environmental Health.
Is Comfort in Kendall County or Kerr County?
The town of Comfort sits in western Kendall County, though the school district reaches into Kerr County. For a specific parcel right at the line, confirm which county and appraisal district it falls in before you file.
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