Experts probe zoning rules effect on inequality, housing availability in Tennessee

As zoning experts across the country look for a way to increase affordable housing and to redress historical inequalities, they have turned their attention on single-family zoning, a type of rule that only allows single-family detached homes to be built on a property. 

Zoning rules date back to the 19th century, and they’re intimately connected to the history of racist policies like redlining and restrictive covenants, which structurally prevented minorities from accessing wealth in a way that’s still having a measurable effect, scholars say. 

Single-family zoning, in particular, arose as a way to protect the property values of white investment neighborhoods in northern California in the first half of the twentieth century, according to historical studies of the practice. The rules spread across the country, eventually becoming common. Zoning experts suggest that they have cemented racial and class segregation in many areas of America, as well as urban sprawl, an unplanned type of development where housing builds away from the urban area that is linked to longer commutes and greater emissions.

“Nationwide the history of zoning has been one founded on the idea that we need to separate uses and separate classes of people and that has racial consequences in terms of who has more wealth in our society and that’s no different in Tennessee than anywhere else,” said Yonah Freemark, a senior research associate in Metropolitan Housing and Communities for the Urban Institute, a nonpartisan think tank.

Across Tennessee, studies have revealed racial disparities in both homeownership and in the value of the homes owned by racial minorities, partly owing to the history of housing policies that intentionally favored white home-ownership over black. 

A 2020 report from the University of Tennessee, Chattanooga, for instance, said that white homes were worth an estimated 47.01% more than black homes which had increased in value at a slower rate from 1980-2010. That study looked at four major metropolitan areas in the state: Chattanooga, Knoxville, Memphis, and Nashville. 

“I think that the focus on single-family homes has been particularly founded on [the idea] that somehow the single-family home is the ideal form to raise a family and therefore we can’t threaten it,” Freemark said. But now, the country has entered into an experimental phase with zoning, he said. 

Cities and states have moved to undo single-family zoning in favor of more inclusive zoning in the last couple of years. 

At the state level, California enacted a law that eliminated single-family zoning in the state this year. 

Cities like Minneappolis, Minn., and Charlotte, N.C., have also discarded these more restrictive zoning rules.

The ultimate effect of these changes, however, is still somewhat cloudy. 

“Unfortunately, the reality is we just don’t have that much information yet about what zoning reforms are most beneficial. There has not been much research about that,” Freemark said, adding, “This is not to say that getting rid of single-family zoning is a bad policy, but it does mean that we really don’t know which policy to recommend.”

A state-level intervention might spur investment or changes to land use in central Nashville, an area that is gentrifying today, but in more rural areas it might not, Freemark indicated. 

Rural areas tend to have less population density and more undeveloped land. The reasons for a lack of development there can be very different than in more metropolitan areas like Nashville and Memphis, both of which have single-family zoning restrictions written into the metro ordinances.  

The relationship between zoning and community growth isn’t obvious, Freemark stressed. 

The data around the practice are complicated, researchers say, revealing a connection at the national level between restrictive zoning laws and race-and-class segregation. 

The national story, Freemark said, shows a connection between metropolitan areas with stricter zoning rules and segregation. The wealthiest neighborhoods where only single-family are allowed are also the most segregated from a race and class perspective. 

Notably, however, a lot of low-income communities in places like Memphis and even Nashville are fully single-family but also have high rates of poverty, meaning there isn’t a one-to-one relationship between zoning and exclusion.  But what is true, he adds, is that if you only allow single-family zoning in wealthy neighborhoods then you’re making it difficult for people of other backgrounds to participate.

The city of Charlotte decided to allow dense housing, such as duplexes and other multiplexes, in previously single-family zoned areas, during an overhaul of the city’s zoning earlier this year. The decision prompted questions about whether it could serve as a model for the South to grapple with historical injustices since Charlotte is more culturally similar to Tennessee than California. The city is in the process of putting the rules into practice through its Unified Development Ordinance, which is still open for public comment.

There are some reasons for caution. Other recent examples have not made the case as well as scholars had hoped, causing some reluctance. 

The preliminary data concerning the Minneapolis city council’s 2018 vote, for example, has so far revealed a higher demand for more dense development but also a 3-5% increase in housing prices, according to a 2021 study by Daniel Kuhlmann, an assistant professor in the Department of Community and Regional Planning at Iowa State University. 

The removal of single-family zoning restrictions only allow other types of units to get built, they don’t mandate that they will get built, Freemark emphasized.

Another relevant factor for Tennessee is the rural versus metropolitan distinction, as these areas tend to have different demand for housing. 

Data from the National Association of Home Builders on new housing in Tennessee have suggested that more single-family units than multi-family units are being built in the state. The most new housing is in major metropolitan areas, including Knoxville, Memphis, and Nashville, with markedly less new units in metropolitan areas such as Cleveland, Jackson, and Johnson City.

While a state-level bill may have worked for California, it may not provide a useful model for Tennessee, scholars have suggested. 

In Tennessee, zoning rules aren’t often set at the state level. 

Zoning in Tennessee is incredibly regionalized, Kacy Joy, a senior associate with Frost-Brown-Todd LLC, said. 

In Williamson County, for example, there’s Thompson’s Station and then Franklin and then Williamson County property that’s not within any city or its urban growth area, she said. While the ordinances for these areas may overlap some, they’re “each pretty different.”

Because zoning is set at the local and regional level, any attempts to undo the policies would affect different areas in varied ways.  

More local efforts will have to be cautious with their specific wording as well.

Many of the zoning regulatory schemes that are being passed to increase housing affordability may not increase development or housing affordability in practice, an article co-authored by Joy argued.

Earlier this year, for instance, the Metropolitan Council of Nashville approved a detached accessory overlay district in a bid to increase affordable housing. The overlay allows “accessory dwelling units” to be constructed on single-family zoned in some areas of Nashville. A practice that’s been long used in states like California, these units can be added to areas that already have property and can theoretically increase the available housing supply. 

In Joy’s view, the ordinance includes restrictions related to access, lot area, and similar issues make it so that, while the ordinance technically allows for these units to be built, it may not actually increase affordability if the places to which the ordinance applies cannot be built in a way that would satisfy all the requirements. 

Zoning rules have shaped the way the country has developed and will continue to do so. Zoning experts are trying to be thoughtful about how those rules have shaped and have been shaped by discrimination and exclusion. 

State-level policies might not be in a position to solve housing availability in Tennessee, the experts seem to suggest, leaving regional and local policymakers to tackle housing and zoning issues.