Alongside Austin’s glimmering new residential towers and Houston’s townhouse boom, Texas’ famously sprawling suburbs keep growing. Frisco, outside Dallas, is America’s ninth-busiest city for home building. Austin suburbs like Pflugerville and Round Rock and Houston suburbs like Pearland weren’t far behind, far outpacing peers in other fast-growing Sun Belt states.

For all its faults, this growth is mostly a good thing. New housing keeps Texas’ dynamic cities affordable for working- and middle-class households, who continue to arrive from high-cost states like California. But old criticisms endure: Does it all have to look the same? Does it have to take up so much space?

In new research published by the Mercatus Center at George Mason University, we explore these questions by studying one common land-use regulation in Texas’ growing suburbs: minimum lot sizes. These rules require lots hosting single-family homes to be at least a certain size, ranging from only 1,400 square feet in cities like Houston up to as much as two acres in exclusive northeastern suburbs like Sharon, Massachusetts.

Researchers have criticized minimum lot sizes for everything from raising housing costs to hurting the environment. Yet up until now, nobody has taken a hard look at whether they actually force homes to sit on needlessly large lots in practice.

In other words, do most Texas homebuyers actually want lots that big?

Those four booming suburbs — Round Rock, Pflugerville, Frisco and Pearland — hold the answer. If minimum lot size rules don’t suit homebuyers in suburban towns with an open approach to new development and plenty of remaining land left to develop, they probably don’t suit homebuyers in more crowded Texas cities. All it requires is looking at whether actual lot sizes are smaller than (or right at) the legal minimum.

In Round Rock and Pflugerville, new single-family homes must sit on lots of 6,500 and 9,000 square feet, respectively. In Round Rock, just over half of homes were substantially larger than the minimum requirement. In Pflugerville, by contrast, only 19 percent were substantially larger than the minimum required. These simple results suggest that minimum lot sizes are likely forcing up suburban lot sizes, especially in Pflugerville, making housing more expensive than it would be on smaller lots.

Frisco is different in that it offers a range of single-family housing zones for developers to choose from, each with its own minimum lot size. Most of the area zoned for single-family housing allows lot sizes as small at 7,000 square feet. Others set minimums as high as 8,500, 10,000, and 16,000 square feet. Only 33 percent of Frisco lots were well above the minimum, again showing that buyers are forced into large lots in the Dallas area.

Only in Pearland, a suburb of Houston, was there weak evidence that regulation is driving up lot sizes. However, with a range of zoning options, a low minimum lot size of 5,000 square feet, and even more permissive lot size rules next door in Houston, this makes sense. Buyers here can mostly select what they actually prefer.

Texas’ cheap gas, rising incomes, and a surge of new migrants mean that it will continue to expand both upward and outward. But land-use regulations that force homes to sit on larger lots mean more of that growth will be outward sprawl, with uniform suburbs that spread Texans further and further out. Buyers seeking smaller, affordable homes ultimately lose.

Texas’ current boom depends on easy access to cheap land. If regulations like minimum lot sizes use up all the accessible land — or make it too expensive — the Lone Star State’s boom years could be numbered.

Gray is an urban planner in New York and a contributor to Market Urbanism. Furth is a senior research fellow with the Mercatus Center at George Mason University. They are co-authors of the new study, “Do Minimum-Lot-Size Regulations Limit Housing Supply in Texas?”