Katy's Zoning Ordinance defines an Accessory Dwelling Unit as a unit accessory to a principal single-family residence, used only by family members, guests, or employees working within the residence; commercial use is prohibited.
The City of Katy Zoning Ordinance (Exhibit 14A, codified through eCode360) defines an Accessory Dwelling Unit as a dwelling unit accessory to a principal single-family residence for use by family members, guests, or employees working within the residence for the family. The ordinance also defines an 'accessory building or use' as a subordinate building having a use customarily incident to and located on the lot occupied by the main building. The principal dwelling and accessory unit must share single utility metering. The accessory dwelling may have self-contained kitchen and bath facilities and its own outside entrance, but it must remain for the use and convenience of the family and may not be used for any commercial purpose, which rules out renting it as a separate apartment or short-term rental. Texas Local Government Code Chapter 211 grants Katy authority to zone and regulate accessory structures; lots in adjacent unincorporated Harris, Fort Bend, or Waller County areas (Katy ETJ) instead follow county subdivision rules rather than Katy zoning.
Building or occupying an unpermitted ADU can trigger code enforcement action, stop-work orders, and zoning violation citations through Katy's Building Department (901 Avenue C, 281-391-4830). Renting the unit commercially violates the accessory-use definition. HOA covenants in master-planned Katy-area communities frequently prohibit ADUs entirely and are enforced separately from city code.
See how other cities in Fort Bend County handle adu rules.
See how Katy's adu rules rules stack up against other locations.
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