Rolling Texas Hill Country limestone hills with live oak motts, Ashe juniper, and a clear creek over white limestone cobble.
Hays County 2006 IRC or the 2021 IRC as adopted in San Marcos as adopted here

Barndominium Builders in Hays County, TX

Hays County is the county where two Texas stories meet. It is one of the fastest-growing counties in the state, up almost a quarter in five years, and a large part of it sits over the Edwards Aquifer recharge zone, where the state regulates construction on land the county cannot write a building code for. West of the escarpment, around Wimberley, Driftwood and Dripping Springs, is Trinity aquifer acreage country with thin soil over limestone. East of it, Kyle and Buda are I-35 commuter towns growing by subdivision. The rules do not treat those two halves alike, and neither should a builder. On a rural tract the sequence is not what it is in a city: the parcel has to be compliant before anything, the septic design decides how much land you actually need, and the well has a different answer depending on which side of the county it is drilled on.

Hays County at a glance

County
Hays County
Population
304,390
Where we build
Kyle, Comal County, Travis County, Guadalupe County, New Braunfels

ZIPs 78666, 78640, 78610, 78620, 78676, 78619, 78737, 78652 and more

Site visits
Site walks arranged throughout Hays County, Kyle included
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Building conditions in Hays County

What actually changes from one Texas jurisdiction to the next: who issues the permit, whether the residential code is enforced there at all, what the structure has to be engineered to, and what the ground is like. These are the numbers your drawings have to satisfy.

Build conditions for Hays County , Texas . BUILD CONDITIONS HAYS COUNTY, TXHays County2006 IRCADOPTED RESIDENTIAL CODE2006 IRCThis jurisdiction publishes no design wind speed. It is settled in writing with the authority overyour parcel before the frame is ordered.ZONING ·Up to 5 acres for a conventional sep…There is no county zoning. In the county's own words, Hays Countyhas limited zoning authority granted from the State of Texas and…WHO ISSUES THE PERMITHays County Development Services2171 Yarrington Road, Suite 100, Kyle, TX 78640. 512-393-2150, 8amto 5pm Monday to Friday. Development permits, on-site sewage…
Build conditions for Hays County, drawn from the sourced facts on this page. Every figure above is cited in the quick-facts panel below, with its source and vintage.
There is a state permit on the parcel, and it turns on five acres
Construction at a private residence over the Edwards Aquifer recharge or contributing zone falls under TCEQ's Chapter 213 rules, and the plan must be approved before soil is disturbed. TCEQ then publishes four conditions under which an individual plan may not be required for a single-family house: the lot is part of a master community with an approved plan; the lot is larger than five acres with no more than one single-family residence on it; impervious cover is 20 percent or less; or rainwater harvesting brings adjusted impervious cover to 20 percent or less. Impervious cover expressly counts rooftops, driveways, concrete pads and sheds.

TCEQ, Edwards Aquifer: Private Residences, tceq.texas.gov/permitting/eapp/edwards-aquifer-private-residences, page-dated 17 February 2026

The septic table is the real zoning map
Hays County's own sewage order sets minimum lot size by aquifer zone, water source and system type. Over the recharge zone a conventional system on a private well needs 5 acres and an advanced system 3 acres; over the contributing zone it is 3 and 2; everywhere else 2 and 1.5. On surface water or rainwater collection the recharge-zone figures fall to 2 and 1.5. Where two water sources apply, the larger minimum governs, and where the system design itself demands more land, that governs instead.

Hays County On-Site Sewage Facility Regulations, Order of the Commissioners Court adopted 4 June 2013, Sec. 10.D and Table 10-1, approved by TCEQ 18 February 2014

A well is permitted in the east of the county and not in the west
Around Kyle and Buda the Barton Springs / Edwards Aquifer Conservation District requires a permit to drill any new Edwards or Trinity well. Even the exempt class, domestic or livestock use on 10 acres or more, takes a notarised application, a $450 fee, a site building plan, the septic coordinates and a cap of under 7 gallons per minute. Below 10 acres it becomes a Limited Production Permit with a meter and annual reporting. In the west, the Hays Trinity district's statute says a domestic well for one household incapable of producing more than 25,000 gallons a day may not be regulated, permitted or metered, though the landowner must still notify the district before construction.

bseacd.org/types-of-well-permits and bseacd.org/about; Special District Local Laws Code Secs. 8843.103 and 8843.104 as amended by H.B. 3903, 83rd Legislature, 2013

The county opted in, and still inspects nothing
Hays County states that its commissioners court adopted regulations under H.B. 2833 on 15 September 2009, requiring a new house in the unincorporated county to be inspected at least three times: at foundation before concrete is placed, at framing and mechanical before covering, and on completion. The county also states that it does not perform inspections on single-family development and that a builder will be required to contact a third party to complete them. That is Subchapter F working exactly as written: no county permit, no county fee, no county inspector.

Hays County Development Services FAQ, Development and Floodplain, hayscountytx.gov Faq.aspx; Local Government Code Secs. 233.153 and 233.154

Five septic agents in one county, and the pattern is not what you would guess
TCEQ's authorised agent search returns six records for Hays County. The county is the agent for the entire county except the cities of Dripping Springs, Niederwald, San Marcos and Uhland, each of which runs its own programme. Kyle, Buda, Wimberley and Woodcreek are not on the list, so inside those city limits the septic agent is still Hays County. TCEQ prints the rule on the results page: if the city is not listed, contact the county.

TCEQ On-Site Activity Reporting System, authorized agent search for Hays County, county code 105, run 1 September 2026

A permit for any construction, floodplain or not
Hays County requires a development permit for any kind of development anywhere in the unincorporated county, which it defines to include houses, sheds, outbuildings, pools, slabs and foundations, fill, grading and creek crossings, inside the floodplain or outside it. The county's published fee is $100 outside a Special Flood Hazard Area and $300 for a habitable structure inside one. The permit is not a code review of the house: it is good for one year to start construction and two years to finish, and the county explains it exists so the county stays in the National Flood Insurance Program.

Hays County Development Services FAQ and Floodplain page; Hays County Development Services Fee Schedule effective 1 January 2026

Also worth knowing before you build in Hays County

The shop bay does not enlarge the drainfield
Texas sizes a single-family septic system from the number of bedrooms or the living area of the home, whichever gives the larger figure, so a 1,800 square foot three-bedroom living space with a 2,200 square foot shop is a 300 gallon-per-day house rather than a 375. An authorised agent is allowed to be stricter and some Texas counties are. Hays County's order lists its stricter rules exhaustively at Section 10 and none of them redefines living area. What it does add is a rule about second structures: a garage apartment, pool house or guest cottage keeps the lot in the single-family class only if its usable floor space is under half the primary dwelling's, it is not offered for public use or rental, and it cannot be sold separately.

TCEQ form TCEQ-0235 item 8 and 30 TAC Ch. 285 Table III; Hays County On-Site Sewage Facility Regulations Sec. 10 and Sec. 10.D.4

Ten acres buys you nothing here either
The belief that ten acres exempts a house from the septic rules is wrong statewide, and TCEQ said so in its own words when it amended the rule in 2023 because the old wording had been misinterpreted as an exemption from the entirety of Chapter 285. Hays County forecloses it in county text: a permit is required for all on-site sewage facilities regardless of the size of the lot or acreage onto which it is installed.

Hays County On-Site Sewage Facility Regulations Sec. 10.W.1; 30 TAC Sec. 285.3(f)(2) as amended 2023

Rental changes who may build the system
Hays County states that a homeowner can install their own residential on-site sewage facility, and that only a licensed installer can install a system used for commercial use, including rental houses. The same distinction runs through the order: a group of rental dwelling units is sized as non-residential at one acre per dwelling unit equivalent, and the county's published OSSF application fee is $610 for a single-family residence against $910 for a non-single-family one. A barndominium intended as a guest house or a short-term let is not automatically on the same track as the one you live in.

Hays County Development Services FAQ, On-Site Sewage Facilities; Hays County OSSF Regulations Sec. 10.A.1 and 10.D.1(C); Development Services Fee Schedule effective 1 January 2026

No plat, no permits at all
The county states that if a property that is required to be platted is not, the owner will be unable to get any county approvals including development authorisations, on-site sewage facility permits or driveway permits, and that non-compliant property will be unable to legally develop in Hays County. The sewage order says the same from the other side: only lots platted under county regulations, or legally in existence before the order took effect, are eligible for a permit. The county sells the answer in advance for a $100 parcel compliancy determination, and a pre-development meeting with staff can be booked online.

Hays County Development Services FAQ, Planning and Subdivisions; Hays County OSSF Regulations Sec. 10.C.1; Development Services Fee Schedule effective 1 January 2026

Dividing land brings a water availability test with a six-acre answer
Hays County requires a water and wastewater service plan for a subdivision plat. Where individual wells will serve new development in a Priority Groundwater Management Area, the certifier must obtain historical water levels from the groundwater district, walk the perimeter looking for undocumented wells, confirm documented wells within 500 feet, and estimate annual recharge with a Texas Water Development Board approved groundwater availability model. Where projected withdrawal exceeds estimated recharge, the minimum lot size becomes 6 acres, or the applicant prorates it against another supply, or offsets it by putting other land under a perpetual conservation easement.

Hays County Development Regulations Ch. 715 Secs. 1.01, 3.04 and 3.06 and Ch. 705 Table 705.05.01, revised version 17 January 2025

Hit a void and everything stops
Over the recharge zone the ground itself is a regulated feature. TCEQ defines a sensitive feature as a permeable geologic or artificial feature where surface water may reach the aquifer rapidly, and requires that on discovering one during construction all regulated activities near it stop immediately and TCEQ is notified. A Texas-licensed professional geologist must evaluate it, no construction or soil-disturbing activity may proceed until TCEQ approves a protection plan, and TCEQ has one week to review a complete plan. Typically no activity should occur within 50 feet of the feature meanwhile.

TCEQ, Edwards Aquifer: Sensitive Features Encountered During Construction, tceq.texas.gov/permitting/eapp/sensitive-features-encountered-during-construction

Two feet above the base flood, and the maps are being redrawn
Hays County's flood damage prevention chapter requires the lowest floor, including basement, machinery and electrical equipment, to be at least two feet above the base flood elevation in the 100-year floodplain. The county cites Texas Water Code Secs. 16.313, 16.315 and 16.318 as the authority. It also states that its current flood hazard data dates back to the late 1970s through the late 1990s and that preliminary updated maps are in circulation, so a tract's flood status is worth checking against the county's own map viewer rather than an old certificate.

Hays County Development Regulations Ch. 735 Secs. 1.02 and the elevation standards, revised version 17 January 2025; Hays County Floodplain page

Other people's rules reach unincorporated land
The county lists in its own regulations the outside water quality rules that govern parts of the unincorporated county: Austin's environmental ordinances in Austin's extraterritorial jurisdiction, and the water quality ordinances of Buda, Dripping Springs, Kyle and San Marcos in theirs; the Lower Colorado River Authority's Highland Lakes Watershed Ordinance in parts of western Hays County; TCEQ's Edwards Aquifer program over the recharge and contributing zones; and TCEQ's construction stormwater permitting program for any construction disturbing more than one acre anywhere in Hays County.

Hays County Development Regulations Ch. 725 Sec. 4.03, revised version 17 January 2025

The county is three markets, not one
Hays County's population estimate rose from 243,984 on 1 July 2020 to 304,390 on 1 July 2025, up 24.8 percent across 677 square miles. The growth is not evenly spread. Kyle went from 46,431 to 69,917, up 50.6 percent, and Dripping Springs more than doubled from 5,122 to 11,167. Wimberley went from 2,888 to 2,909, a gain of 21 people, and its density inside its own city limits is about 325 per square mile. The I-35 side is filling in by subdivision while the western county stays acreage country.

U.S. Census Bureau vintage 2025 county and sub-county population estimates and the 2024 Census Gazetteer county and place files

A licensed plumber is required even where nothing else is
The rural exemption in the Texas plumbing licence law expressly excludes plumbing performed in conjunction with new construction. Alongside it, a builder working outside the limits of any municipality must certify that the house complies with the state energy code and keep that certification for three years. Both apply on land with no building permit and no county inspector.

Texas Occupations Code Sec. 1301.052; Texas Health and Safety Code Secs. 388.003(a) and 388.004

An excavator grading a compacted building pad on a cleared lot, with survey stakes and a drainage swale visible.
Below the slab

The expensive surprises are in the ground, not the building

What moves a Texas budget is usually below grade, and it is soil rather than rock: shrink-swell clay. The Blackland Prairie and the Gulf Coast clays move enough between a wet season and a dry one to drive the foundation design across the state's largest markets, which is why several DFW cities require an engineer's seal on the foundation of every new house. Those are the same conditions that decide whether a septic field passes its soil and site evaluation, so the grading plan, the foundation and the drainfield get resolved together rather than one at a time. We price the dirt before we price the building.

What we build in Hays County

All nine of our services — kits, custom plans, post-frame and steel construction, site preparation, permitting and engineering, through to turnkey builds — are available across Hays County. What a project costs depends far more on the parcel than on square footage, so we work from your land rather than from a rate card.

See what we build

What a build looks like

Three stages every Hays County project passes through, from a raw parcel to a finished home. Site work first, because that is where the budget is decided.

Aerial view of an undeveloped rural lot with cleared grass, a live oak and cedar elm treeline, and a pale gravel access track.
Stage one

The parcel

Zoning, setbacks, flood zone and utility access get checked before anything is drawn.

An excavator grading a compacted building pad on a cleared lot, with survey stakes and a drainage swale visible.
Stage two

Pad and permit

Clearing, grading and a compacted pad, while the submittal works through Hays County.

A finished barndominium at dusk with warm interior lighting glowing through its large windows.
Stage three

Frame to finish

Shell erected and dried in, then systems, insulation and interior finish through to CO.

Those are the rules for Hays County. Tell us what you want to build and we will draw it to them.

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Where we build around Hays County

Hays County and the rural land around it. The buildable acreage for a project this size usually sits outside the city limits, which is frequently what changes who issues your permit.

Our Hays County service area, covering Hays County and the surrounding rural acreage. This map marks the territory we serve, not a branch location.

Keep reading

The questions that usually come next once you know what Hays County allows.

Barndominium Cost Guide

Sourced per-square-foot ranges by tier and by size, with a calculator built on the same figures.

Read it

Is It Legal in Texas?

Classification, zoning, the HOA gate, and why "nonresidential farm building" does not cover a home.

Read it

How Long Does It Take?

Census build-duration data, and what actually sets the permit clock where you are building.

Read it

Nearby areas we build in

Others we cover in this part of Texas. The permitting authority, the adopted design criteria and the zoning can all differ from one to the next.

Comal County

Comal County
Travis County

Travis County
Guadalupe County

Guadalupe County
New Braunfels

Comal County

Building in Hays County: common questions

9 questions we get asked most often about building in Hays County. If yours is not on the list, ask it directly.

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Do I need a building permit for a barndominium on unincorporated land in Hays County?
Not a building permit in the sense a city means it, but Hays County is not a no-paperwork county either, and the difference matters. Chapter 233 of the Local Government Code is the whole of a Texas county's authority over structures and it has no general building-code subchapter. Hays did take up the one optional piece, Subchapter F: the county states its commissioners court adopted regulations under H.B. 2833 on 15 September 2009, which is why a new house here carries a Notice of New Residential Construction and three inspections, at foundation before concrete, at framing and mechanical before covering, and at completion. The county performs none of them. In its own words a builder is required to contact a third party to complete the inspections, and the statute allows the county no permit, no fee and no plan review for it. What the county does issue is a development permit for any construction at all, and the septic permit. Inside San Marcos, Kyle, Buda, Dripping Springs, Wimberley, Woodcreek, Uhland or Niederwald, that city's code and its building official apply instead.
My land is over the Edwards Aquifer recharge zone. Does that stop me building?
No, but it puts a state permit on a parcel the county cannot write a building code for, and it is worth understanding as a threshold rather than a wall. TCEQ's Chapter 213 rules apply to construction at a private residence over the recharge zone or the contributing zone, and the plan has to be approved before soil is disturbed. TCEQ then publishes four ways a single-family house avoids needing an individual plan: the lot is part of a master community with an approved plan; the lot is larger than five acres with no more than one single-family residence on it; impervious cover is 20 percent or less of the property's legal boundaries; or a rainwater harvesting system brings the adjusted impervious cover to 20 percent or less. Impervious cover counts rooftops, driveways, concrete pads and sheds, which on this building type means the shop roof and the apron count too. Twenty percent of a single acre is 8,712 square feet of roof and paving, so on real acreage the arithmetic is usually comfortable. Note the acreage limb says larger than five acres, not five, and the county's own conventional septic minimum over the recharge zone is exactly five, so the two tests sit next to each other without being the same test. TCEQ's Austin regional office covers Hays on 512-339-2929.
How much land do I actually need?
More than the state minimum, and how much more depends on where in the county you are and how you get your water. Texas sets half an acre on a public supply and one acre on a private well. Hays County's own sewage order replaces that with a table keyed to the Edwards Aquifer zone, the water source and the system type. Over the recharge zone on a private well it is 5 acres for a conventional system and 3 for an advanced one. Over the contributing zone it is 3 and 2. Everywhere else in the county it is 2 and 1.5. If the water comes from surface supply or rainwater collection rather than local groundwater, every figure drops. Where two water sources apply the larger minimum governs, and if the system design itself needs more room, that governs instead. Older lots are treated separately: a lot platted before 14 March 1977 may take a system at any size, and there is a ladder of minimums for lots platted between then and 1997. So the honest answer is that the site evaluation, not the listing, decides whether a tract works, and it is the first thing worth buying.
Do I need a permit for my well?
It depends which side of the county you are on, and this is the single sharpest split in Hays County. Around Kyle and Buda you are in the Barton Springs / Edwards Aquifer Conservation District, which states plainly that a permit is required to drill a new Edwards or Trinity well. Even the exempt class, solely domestic or livestock use on a property of 10 acres or more, takes a notarised application, a $450 fee, ownership documentation, a site building plan, the well and septic coordinates and a well schematic, and the permitted well is capped at under 7 gallons per minute. If the property is smaller than 10 acres it becomes a Limited Production Permit instead, which needs a user conservation plan, a meter and annual meter readings, and is capped at 250,000 gallons a year. In the west of the county, around Dripping Springs and Wimberley, the Hays Trinity Groundwater Conservation District's enabling statute says a well used for domestic use by a single private residential household and incapable of producing more than 25,000 gallons a day may not be regulated, permitted or metered by the district, though the landowner must still notify the district before constructing a new well. Confirm which district your parcel is in before you budget.
Who issues the septic permit, and does living inside a town change it?
Yes, and not in the way most people expect. TCEQ's authorised agent search returns six records for Hays County. Hays County is the agent for the entire county except the cities of Dripping Springs, Niederwald, San Marcos and Uhland, each of which runs its own on-site sewage programme. Kyle, Buda, Wimberley and Woodcreek do not appear, which means that inside those city limits the county is still your septic authority. TCEQ prints the disambiguation rule on the same page: if the city is not listed, contact the county. Nothing about a town's size or character predicts which way it falls, so check rather than assume. Hays County Development Services is at 2171 Yarrington Road, Suite 100, Kyle, on 512-393-2150, and applications go through MyGovernmentOnline; the county does not accept paper.
Everyone says rural Texas has no rules. What actually applies out here?
Quite a lot, and almost none of it is a building code. There is no county zoning, and the county says so itself: it has limited zoning authority granted by the state and recognises only airport zoning around the San Marcos Regional Airport. But a development permit is required for any construction, fill, grading or creek crossing anywhere in the unincorporated county, at $100 outside a Special Flood Hazard Area and $300 for a habitable structure inside one. The septic system needs a permit and an inspection on any size tract. The floodplain rules require two feet of freeboard above the base flood elevation. TCEQ's construction stormwater permit applies to any project disturbing more than an acre, anywhere in the county. Over the aquifer, TCEQ's Chapter 213 rules apply, and if the excavator opens a cave or a solution cavity, work stops until TCEQ approves a protection plan. A licensed plumber is required on new construction even where nothing else is, and a builder outside any city must certify the house against the state energy code. And in Texas, recorded deed restrictions do the work zoning does elsewhere, so read the title commitment.
Is there a percolation test?
No. Texas does not use the percolation method at all. A site evaluator or a professional engineer classifies the soil by texture into classes Ia through IV, and each class carries a loading rate in gallons per square foot per day, from which the required absorptive area is calculated. A site can fail at either end: heavy clay at the bottom of the range needs a very large field, and TCEQ's rule says outright that Class Ia sandy and gravelly soils do not provide adequate treatment of wastewater through soil contact, so the remedy there is imported soil or secondary treatment with disinfection. In much of Hays County the constraint is a third one that neither end of that scale describes, which is depth of soil over rock. The county's own order shows it: a spray irrigation site must be cleared of exposed rock, or the exposed rock covered with at least four inches of soil that will support vegetation, and the spray field may not exceed a 15 percent slope in any direction.
I want to build in Wimberley or Dripping Springs and let it out part of the year. Does that change anything?
It can, and it is worth settling before the plans are drawn rather than after. Hays County states that a homeowner may install their own residential on-site sewage facility, and that only a licensed installer may install a system used for commercial use, including rental houses. The county's sewage order also treats a group of rental dwelling units as non-residential, sized at one acre per dwelling unit equivalent, and it keeps a second structure such as a guest cottage or garage apartment inside the single-family class only if its usable floor space is under half the main house, it is not offered for public use or rental, and it cannot be sold separately. The published application fee is $610 for a single-family residence and $910 for a non-single-family one. The county publishes nothing on how its Fire Marshal treats a let single-family house under the International Fire Code, which the county applies to commercial, multifamily and public buildings, and at least one other Texas county routes anything that is rented out through its commercial office at a higher fee and a different code. That is one phone call to the Hays County Fire Marshal on 512-393-7300, and it is worth making it early.
I am thinking about splitting a tract. What should I know first?
That platting is the gate before every other gate. The county states that if a property required to be platted is not, you will be unable to obtain any county approvals, including development authorisations, on-site sewage facility permits or driveway permits, and that non-compliant property cannot be legally developed in Hays County. The sewage order repeats it from the other side: only lots platted under county regulations, or legally in existence before that order took effect, are eligible for a septic permit. If you are dividing land you will also need a water and wastewater service plan. Where individual wells will serve new lots inside a Priority Groundwater Management Area, the person certifying groundwater availability has to gather historical water levels from the groundwater district, walk the perimeter looking for undocumented wells, confirm documented wells within 500 feet, and model annual recharge with a Texas Water Development Board approved model. If projected withdrawal exceeds estimated recharge, the minimum lot size becomes 6 acres unless the applicant prorates against another water supply or offsets it with land placed under a perpetual conservation easement. The county will tell you where a parcel stands for a $100 compliancy determination, and a pre-development meeting can be booked online at no charge.

Building in Hays County?

Start with the plan. Tell us what you want to build and we will draw it, then confirm what Hays County will actually let you put on the parcel and what wind load it has to meet. That conversation costs nothing.

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