Permit Required? Required
Typical Fee Range $1,000–$4,000 Includes building permit, separate trade permits, and wastewater capacity reservation fees.
Fee Method Valuation-based
Apply Online Apply at Houston Permitting Center →

What's Required in Houston

  • ADUs are permitted on single-family lots but cannot exceed 900 sq ft or 50% of main house.
  • Must have independent kitchen, bathroom, and a separate entrance.
  • Requires a Wastewater Capacity Reservation (WCR) letter from the city.
  • Must follow Chapter 42 zoning setbacks (recently relaxed in some areas to 3–5 feet).
  • Must be located on a lot with an existing primary residential structure.
  • Separate utility meters are optional but require individual trade permits for setup.

How to Get a ADU Permit in Houston

1

Step 1: Wastewater Reservation

Apply for a WCR letter to ensure city sewer capacity for the new unit.

2

Step 2: Professional Plans

Hire an architect to create structural, plumbing, and electrical drawings.

3

Step 3: iPermits Submission

Submit the 'Building Residential - New' application via the portal.

4

Step 4: Fee Payment

Pay valuation-based permit fees and sewer impact charges.

5

Step 5: Full Inspection Series

Schedule Foundation, Framing, Rough MEP, Insulation, and Final inspections.

Frequently Asked Questions

Yes, Houston allows ADUs up to 900 square feet on single-family properties.
Total city fees typically start around $1,500, not including plans or construction.
No, secondary dwelling units are generally exempt from additional parking mandates.