City vs. Unincorporated Area
Living Outside Houston City Limits in Harris County Is Common
A large portion of Harris County's population lives in unincorporated areas — outside any city — which means different rules for zoning, permits, and services.
Unincorporated Harris County means no city claims your address. You pay county taxes and follow county rules. Your water and sewer may come from a MUD (a special utility district). Harris County does not have traditional zoning, so land-use rules are looser than in most places.
Texas cities have an ETJ — an Extraterritorial Jurisdiction. This is a buffer zone just outside city limits. Cities can control some things in that zone, like how new subdivisions are built. If your address is in a city's ETJ, find out what rules apply to you. The Harris County Office of County Engineer handles permits for unincorporated areas. The Harris County Office of Economic Development at hcoed.harriscountytx.gov has resources to help you identify whether your address falls in a city, ETJ, or unincorporated area.
Source to confirm: Harris County Office of Economic Development