Barndominium Builders in Austin, TX

Barndominium builders working around Austin have to deal with two different kinds of country. Austin is the county seat of Travis County and sits at the foot of the Balcones Escarpment on the Colorado River. The city straddles the Balcones Fault, so the eastern side is mostly flat with heavy clay and loam soils, while the western side rolls into the edge of the Texas Hill Country over limestone. A barndominium on a few acres near Manor and one on a cedar-covered lot past Lake Travis can need very different foundations, septic systems and site work.

Two counties in one

Travis County covers 1,023 square miles, 990 of them land. The western part is karst Hill Country, limestone with caverns and springs such as Barton Springs and Hamilton Pool. The eastern part is plains and old farmland that was planted in cotton for generations. Before we price a shell, we want to know which side of the fault your property is on.

East of I-35: Houston Black clay

The official USDA description for the Houston Black soil series lists its type location in Travis County, near Manor. It is a Blackland Prairie clay with high shrink-swell potential. In dry spells it cracks open, with cracks 0.5 to 4 inches wide that run 12 inches or deeper, and in most years those cracks stay open for 90 to 150 days in total. Permeability is very slow and runoff is high. For a steel or post-frame barndo, that means the slab design, the moisture control around the perimeter and the drainage around the building all matter more than the wall panels.

West of Austin: rock and runoff

On the Hill Country side the problem flips. Thin topsoil over limestone means excavation can turn into rock work, and the city's own history notes that this thin topsoil makes parts of the area prone to flash floods from thunderstorm runoff. Pad placement, driveway crossings and where water leaves your lot get worked out before the slab is formed.

Who issues the permits

Inside Austin city limits, the city's codes apply. In the city's extraterritorial jurisdiction, Texas law says the municipality's adopted building code controls. Out in unincorporated Travis County, the rules are set by Chapter 233, Subchapter F of the Texas Local Government Code for counties it covers. Section 233.153 requires new single-family homes and duplexes there to meet the International Residential Code as published May 1, 2008, or the version used in the county seat. It also says the subchapter does not require county approval before new residential construction begins and does not give the county zoning power. Deed restrictions and HOA covenants are a separate question, and we ask for them early because some subdivisions limit metal siding.

Septic on rural Travis County lots

Most acreage outside city utility lines needs an on-site sewage facility. The Texas Commission on Environmental Quality runs the statewide OSSF program and keeps a county map showing the authorized agent that handles septic permits for each county. A site and soil evaluation comes first; tight clay in the east and shallow rock in the west both narrow the choice of system.

Weather to build for

Austin's records run from 112 degrees, reached in September 2000 and August 2011, down to minus 2 in January 1949. The area sits on the far southern edge of Tornado Alley by most classifications. We size insulation, HVAC and roof design for long hot summers and the occasional hard freeze.

Room to grow

Travis County grew from 1,024,266 people in 2010 to 1,290,188 in 2020, a 26 percent jump.

Have land in Travis County or under contract? Call (254) 401-5175 or

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and tell us where it is.