Houston has seen a gentle density revolution since the 1990s. Allowing neighborhoods to opt out of citywide reforms was crucial.

From the article:

It’s sometimes said that Houston has ‘no zoning’ – in fact, it’s the first thing the city planning department says on its website – but it is not strictly true. Unlike many cities, Houston does not have a comprehensive set of rules determining how every plot of land can be used, whether residential or otherwise. But it does have regulations limiting what you can build and where. Houston’s Code of Ordinances – its planning rulebook – sets limitations like minimum lot sizes (how big a plot of land must be used for each residential property), how far the building must be set back from the street, requirements for the number of parking spaces that must be included with the development, and much else. Historically, this set of regulations, which require a lot of land for each property, combined with the city’s permissive attitude to building outwards, led to Houston’s characteristic sprawl.

In 1998, a major change was made to the Code of Ordinances. The minimum lot size of a plot within the I-610 motorway which circles Houston’s inner suburbs was dropped from 5,000 square feet – about the size of a professional basketball court – to 1,400. This allowed landowners to divide (or ‘replat’) existing lots into much smaller parcels. The reform also changed the rules around property setback from the street, reducing the minimum required from 25 feet to as little as five feet. Whereas previously a landowner with a 5,000 square feet parcel would have generally been constrained to build one home, set back far from the street and with a lot of land surrounding it, now they could build three homes, for three times as many families.

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The immediate impact of these changes was a boom in a new style of development that has transformed some of Houston’s inner neighbourhoods: Houston townhomes. These homes, while generally still detached, are taller and narrower than the low-density suburban-style homes that are more typical of Houston’s twentieth century development pattern.

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[P]erhaps the Texan character does come into it. M. Nolan Gray, author of a recent book on American zoning, told me that Houstonians he spoke to really did value the right to decide how their own land is used. But Houstonians can be as hostile to new developments in their neighbourhood as residents of any other city. So it’s not just the local character that’s different.

What most makes Houston different is that it had an in-built system to allow residents of small geographic areas to opt out of citywide zoning rules, and of changes to those rules. This opt-out system may explain why city-wide reforms were able to pass, and why they have had the staying power to last several decades relatively uncontroversially.

As mentioned earlier, Houston sets relatively limited rules about land use at the city level. Instead, many rules around land use are set within private ‘deed restrictions’. These are private agreements between landowners within blocks or small areas. When you buy a home in Houston, it may come with deed restrictions determining how you can use the land. [...]

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In 2001, new legislation was passed to make opting out even easier, by allowing local homeowners to petition the city to introduce a special minimum lot size (SMLS) even without going through the legal process of altering the deed restrictions.

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This opt-out system is probably the main reason the 1998 reforms were able to pass in the first place. Cities across the world have been locked into vicious battles over densification policies – and even in the cases where they successfully pass, the pressure to repeal them can be overwhelming.

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Houston’s system allows homeowners to opt out without bringing housing supply in other areas down with them. When homeowners who want to prevent some development nearby are required to have this battle at a higher geographic level of political decision-making, there is a risk that their attempt to stop even one building results in policies that prevent it across a much larger area.

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What this means in a practical sense is that a Houstonian homeowner can opt to have more stringent restrictions on what gets built nearby, but it affects their own property in an obvious and direct way. If they want to set a minimum lot size of 5,000 square feet in their block, they can; but their own property will be worth less should they choose to sell it in the future. So they must decide: what’s worth more to me, the additional value to my property from the right to replace one home with two, or preventing my neighbours from having the same right?

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Much like how the Houston opt-out system prevents individuals from imposing their own preferences on neighbours who don’t share them, sunset clauses do this for future residents. In other places, a restriction preferred by a few residents can not only be imposed on much larger areas, it is also imposed on them indefinitely, long after the residents with the preference are gone. It is simple for people who want to renew local development restrictions in Houston to renew them, but crucially they have to show they want to (and take on the organisational cost).