Building permits, zoning and septic rules in Travis County, Texas

Travis County requires a Basic Development Permit for residential and commercial construction outside incorporated city limits¹. The permit is a county development permit rather than a full municipal-style building permit, and property in a city's extraterritorial jurisdiction may also need municipal approval⁸. New single-family houses and duplexes in unincorporated Travis County must follow the applicable International Residential Code standard, while qualifying manufactured and modular homes are outside that county residential-code definition². Professional builders of new single-family homes must arrange at least 3 third-party inspections: foundation before concrete, framing and mechanical before wall covering, and completion; manufactured homes do not have that inspection requirement⁹. Professional builders or remodelers of one- and two-family dwellings must submit 3 inspection reports on completion, covering foundation, framing/mechanical and final inspections³. The county has a published fee schedule, but applicants should use the current schedule for their location because fee categories differ inside and outside Austin's extraterritorial jurisdiction¹².

Travis County Development Services administers the county's building-related development permit and can be reached at (512) 854-4215⁹. The office is at 700 Lavaca, Suite 540, Austin, Texas, and its permit mailing address is P.O. Box 1748, Attn: Permits, Austin, TX 78701⁹. Basic Development Permit applications are submitted online through MyPermitNow, where applicants upload the relevant site plans, checklists, engineering materials, project data and construction-cost estimate⁵. Development Services returns review comments through the same system, and separate driveway or septic applications may be necessary⁵. Austin issues building permits for work within its zoning jurisdiction, subject to specified exemptions¹³. Elgin, a city mainly in Bastrop County that reaches into Travis County, also issues its own building permits inside city limits¹⁴. Septic approval remains separate: Austin Water handles septic systems in its full jurisdiction and applicable annexed areas; Travis County remains the septic authority where county jurisdiction applies^5,6. For an Elgin septic project, ask Travis County Development Services to confirm the authorized permitting jurisdiction before applying^9,15.

Travis County does not have zoning authority over unincorporated land, so the county cannot use zoning to control property use, building height or size, or residential density there⁴. Austin administers its own zoning districts and site-development rules inside city limits¹⁶. Elgin, which reaches into Travis County from Bastrop County, also administers city zoning¹⁷. Septic jurisdiction is separate: Austin Water handles septic systems in its applicable jurisdiction, while Travis County handles septic systems where county jurisdiction applies^5,6. No county zoning does not mean a rural parcel is unrestricted: the Basic Development Permit, residential-code standard, subdivision rules and floodplain requirements can still govern a project^1,2,10. Before relying on that answer, confirm whether the parcel is within city limits or a city's extraterritorial jurisdiction, because municipal rules may change the permit path^4,8.

Travis County requires a separate septic application where an on-site wastewater system will be used⁵. Travis County's nonresidential checklist requires septic construction approval before the development permit, with a possible written placement-responsibility exception; for a home, ask Development Services to confirm the approval sequence^9,18. Required septic inspections depend on the system and project¹⁹. Travis County is the authorized agent for unincorporated areas and municipalities covered by interlocal agreements, but Austin regulates systems in its applicable jurisdiction and on properties fronting Lake Austin or its tributaries^5,6,20. LCRA regulates the Lake Travis area, but county materials describe conflicting boundaries; ask the responsible authority to confirm the parcel before applying⁷. Travis County's septic inspection team is reached at 512-854-4438, and inspection requests must enter MyGovernmentOnline before 2 p.m. on the previous working day¹⁹. Only about 4.2% of Travis County soils are rated “not limited” for a conventional drain field, so a site evaluation may materially affect the system design and budget²¹. State law has a narrow exemption for a qualifying single-family system on at least 10 acres, subject to every listed condition and any stricter local rule¹⁵.

Unincorporated Travis County has no county zoning rule that sets RV occupancy, tiny-home occupancy, a zoning-based minimum home size or residential setbacks²². That answer does not waive the Basic Development Permit for construction outside city limits or the county's limited residential-code rules for a new house or duplex^1,2. A tiny home treated as industrialized housing follows the applicable state industrialized-housing code and permitting framework rather than escaping regulation because it is small^23,24. Any occupied setup still needs a lawful wastewater solution; Travis County requires a separate septic application where an on-site system is used, while Austin or LCRA may be the responsible authority in their areas^5,6,7. Ask Travis County Development Services to confirm the wastewater approval sequence for the proposed home⁹.

1. Confirm whether the parcel is outside corporate city limits and whether a municipal extraterritorial jurisdiction adds another approval layer⁸.
2. Check the plat, subdivision status and floodplain constraints before fixing the house, driveway and septic locations^1,10.
3. Apply online for the Basic Development Permit and upload the applicable plans, checklists, engineering documents, project data and cost estimate⁵.
4. Confirm whether Travis County, Austin Water or LCRA handles septic, and ask Development Services which septic approvals must precede the home's development permit^5,6,7,9.
5. Obtain a Travis County driveway permit for access to a maintained county road, or work with TxDOT for a state-highway connection⁵.
6. For professional-builder or remodeler work covered by the residential standards, submit the foundation, framing/mechanical and final inspection reports on completion³.

Start with jurisdiction: city limits, a municipal extraterritorial jurisdiction, Lake Austin frontage and the Lake Travis area can change which office reviews zoning, development or septic work^4,6,7,8. Check floodplain mapping and the recorded plat before choosing a building site, because floodplain approval and subdivision rules operate even where county zoning does not^1,10. Confirm legal road access and budget for a driveway permit if the connection is to a maintained county road⁵. For subdivision projects, document water and wastewater availability for every lot and phase; public-water proposals need supply documentation, while septic proposals use the county's OSSF planning route²⁵. Private-well permitting can depend on the applicable groundwater conservation district, so identify the district before assuming a well is exempt²⁶. Finally, account for difficult septic soils: only about 4.2% of Travis County soils are rated “not limited” for a conventional drain field, so a site evaluation may identify a need for an engineered system²¹.