Houston is the only major U.S. city without a formal zoning code, but the metro seems to have a unique "de-facto zoning" system when you combine all the land use regulations the city has according to the Chronicle's Erin Mulvaney.
Houston's patchwork of regulations, which includes historic preservation districts, minimum lot sizes, tax increment reinvestment zones and airport land use controls, can be considered a system of zoning. Most ordinances are "opt-in" policies, where neighborhoods can lobby to create certain restrictions for their communities.
“Houston is famous for being an un-zoned city, but I suggest that it’s not all that it seems,” said Matt Festa, law professor at South Texas College of Law. “It looks and smells like a regular zoned city. We have a lot of regulations." Festa made it clear his research does not take a point of view on whether Houston’s methods are an effective or equitable model. He said there are some drawbacks to the system, including that not everyone has access to the ways to regulate land use.