McLennan County, Texas Building Permit Guide

Census Bureau estimates for 2025 put 44,741 McLennan County residents in the unincorporated balance of the county. Waco has 147,788, followed by Hewitt (16,754) and Robinson (13,028).

This guide covers McLennan County’s residential building requirements, floodplain, plat and culvert rules, the joint septic program and the City of Waco.

What requires a permit in McLennan County?

McLennan County adopted the Chapter 233 residential building provisions of the Local Government Code on October 13, 2009 (order revised September 15, 2020). In unincorporated areas, new homes and improvements that increase square footage or value by more than 50 percent must be built to the International Residential Code that applies in the county seat.

The county does not inspect or charge fees for homes. Instead, the builder must:

• notify the county of the location, approximate completion date and IRC version;
• obtain 3 inspections at different construction phases;
• send the inspection compliance notice to the County Engineer’s Office, 215 N 5th St, Ste 130, Waco.

Under state law the builder hires a licensed engineer, architect, inspector or ICC-certified inspector for these inspections. Failing to submit the reports is a Class C misdemeanor; the requirement does not cover manufactured or modular housing, and penalties do not apply to an owner-builder building their own primary residence.

Who handles permitting in McLennan County?

County Engineer’s Office (floodplain, plats, culverts, residential notices): 215 N. 5th St., Suite 130, Waco, TX 76701; 254-757-5028 (mapping 254-757-5067); Monday to Friday 8 a.m. to 5 p.m.

Septic (OSSF): for unincorporated McLennan County, its cities and Waco, the Waco-McLennan County Public Health District runs the program under an agreement between the city and county: 401 Franklin Avenue, Mae Jackson Development Center, 1st Floor; (254) 299-2473; 8 a.m. to 5 p.m., Monday to Friday. A septic application needs either a plat or a plat-exemption affidavit.

Waco: Inspection Services, a division of Development Services, Dr. Mae Jackson Development Center, 401 Franklin Ave., Waco, TX 76701; (254) 750-5612; permits@wacotx.gov; Monday to Friday 8 a.m. to 5 p.m.

Floodplain, plats and culverts on county land

Floodplain

All development in unincorporated McLennan County must comply with the county’s flood damage prevention order; FEMA’s revised map panels took effect December 20, 2019. For a floodplain determination, give the Engineer’s Office a survey or drawing showing the tract, the fronting road and the nearest intersection. A floodplain development permit requires an elevation certificate within 10 business days of completing the foundation.

Plat exemptions

An owner claiming a plat exemption under Section 1.7 of the Subdivision Regulations gets an affidavit from County Engineering, signs it before a notary and files it with the County Clerk.

Driveway culverts

Call County Engineering at 254-757-5028 and mark the location. The precinct foreman sizes the pipe, Engineering quotes an installation price, and the county installs after payment (checks, money orders and cash only). Owners who install their own culvert must follow the county culvert order.

McLennan County permit costs and fees

• OSSF (from October 1, 2026): conventional $510.00 single-family or $610.00 commercial; aerobic $710.00 single-family or $810.00 commercial; plus a mandatory $10.00 TCEQ fee on every permit
• Plats: preliminary $100 plus $10 per lot; final with an approved preliminary $50 plus $5 per lot; replat/amended plat $50 plus $25 per affected lot; variance $100 per request; cash not accepted
• Homes under the Chapter 233 rules: no county fee

Inspections in Waco

All inspections must be requested online by 4 p.m. the day before through the Citizen Self Service Portal, and contractors must be registered; later requests are pushed back a day. A reinspection fee applies if a third inspection (second reinspection) is needed. Waco adopted the 2024 International Building, Residential, Plumbing, Mechanical, Fuel Gas and Fire Codes as of January 1, 2026, but kept the 2018 International Energy Conservation Code.

Official McLennan County permitting resources

These are the primary sources behind this guide. Codes, fee schedules and procedures change — confirm the position for your filing date.

• McLennan County residential building requirements
• McLennan County Engineering
• McLennan County floodplain information
• Waco-McLennan County OSSF program
• Waco Inspection Services

Frequently asked questions

Does McLennan County require a building permit for a new house?

No permit and no fee, but new homes in unincorporated areas must meet the IRC used in Waco, with notice to the county, 3 inspections and a compliance notice to the County Engineer.

Do the McLennan County rules cover manufactured homes?

No. The requirement does not cover manufactured or modular housing.

Who issues septic permits in McLennan County?

The Waco-McLennan County Public Health District, (254) 299-2473.

Simplify McLennan County permitting with Alliance Permitting

• Check whether the site is inside a city or on county land, and which office handles each permit there
• Prepare the county septic, floodplain, plat or road paperwork alongside any city building permit
• Track each approval and inspection through to the final sign-off

Alliance Permitting is a permit documentation and submission company in Texas. We prepare your paperwork, file it correctly and coordinate with the permitting authority through issuance. We are not a contractor and we do not perform licensed plan review or inspections; that work stays with your licensed team and the jurisdiction.

This guide is provided by Alliance Permitting for general information about McLennan County permitting. Requirements, fees, and procedures change; confirm details with the permitting authority before relying on them.