Step 1: Are you inside City of Katy limits?
The City of Katy issues permits for property inside city limits. Many homes with a Katy mailing address are in unincorporated Harris County or Fort Bend County instead, and county rules apply there. Check your property tax statement, or have your builder confirm, before you plan permit time and fees.
Inside the City of Katy
- Pools and hot tubs need a permit. The city lists swimming pools (in-ground and above-ground) and hot tubs as work that needs a permit. Patios and carports are on the same list.[1]
- Adopted codes. Katy enforces the 2021 International Building Codes and the 2026 National Electrical Code.[1]
- Online portal. Applications and inspection requests go through the city’s Civic Access Site.[1]
- Who to call. The Building Department is at 901 Avenue C, 281-391-4830.[1]
Unincorporated Harris County
Harris County’s Office of the County Engineer issues residential pool permits here. Outside the floodplain, you submit a site plan and application, and no inspection is required. Inside the floodplain, you also submit a pool electric-disconnect drawing, the pool gets a field inspection, and you need an As-Built Certificate. Processing takes 10 business days.[2] Our Cypress page covers the county process in more detail.
Unincorporated Fort Bend County
Requirements depend on your exact location, floodplain status and utility district. Ask each builder which permits they’ll pull, and look up your flood zone on FEMA’s Flood Map Service Center.[3]
Budget
Angi’s Houston page (updated August 2026) puts most inground pools at $51,832–$100,605, averaging $75,337, and notes that expansive soils mean extra excavation steps.[4] See the full cost guide before you collect quotes.
Questions to ask a Katy pool builder
- Which jurisdiction issues my permit: the City of Katy, Harris County or Fort Bend County?
- Is my lot in a floodplain, and how does that change the paperwork and inspections?
- Does my HOA need to approve plans before you file for the permit?
- Where will the excavated soil go, and is haul-off in the price?
Frequently asked questions
Does the City of Katy require a pool permit?
Yes. The City of Katy lists in-ground and above-ground swimming pools and hot tubs as work that requires a permit. This applies to property inside city limits.
My address says Katy but I'm not in the city. Who issues my permit?
Usually the county. In unincorporated Harris County, that's the Office of the County Engineer. In unincorporated Fort Bend County, county offices apply. Your builder should confirm this before quoting a schedule.
Is a pool inspection required in unincorporated Harris County?
Harris County's Office of the County Engineer says no inspection is required for pools outside the floodplain. Pools in the floodplain get a field inspection and need an As-Built Certificate.
What does HTX Backyard charge homeowners?
Nothing. Participating builders pay HTX Backyard a fee for introductions.
Sources
- City of Katy: Permits & Building
- Harris County Office of the County Engineer: Swimming Pool permit
- FEMA Flood Map Service Center
- Angi: In-Ground Pool Cost in Houston (updated Aug 2026)
Sources checked October 2026. Rules, fees and prices change. Confirm details with the agency, HOA or builder before you commit.
How we make money: HTX Backyard is free for homeowners. Participating builders pay HTX Backyard a fee when we introduce them to a homeowner. We are a matching service, not a contractor, and we do not perform, supervise or guarantee any work.