Most American cities have a zoning designation prohibiting all development except detached single-family homes. Many cities apply this designation to most of their land. We think this designation, usually called R1, should not exist. R1 is inequitable, inefficient, and environmentally unsustainable. It lets a small number of people amass disproportionate property wealth, excludes many others from high-opportunity neighborhoods, and forces others to pay more for housing than they should (Lens & Monkkonen, Citation2016; Reeves, Citation2017).

In many cities, R1 prevents housing development where development would be most beneficial and instead pushes development—and conflict over it—into denser, lower income neighborhoods, onto polluted commercial corridors, and into the undeveloped land outside city boundaries. R1 was born from, and codifies, base and tribal instincts: a desire to set privileged in-groups apart and keep feared or despised outgroups at bay (Nightingale, Citation2012). Its history is explicitly classist and deeply interwoven with racism, and its present form only barely conceals these origins (Rothstein, Citation2017; Trounstine, Citation2018; Weiss, Citation1987). It should have no future. Planners should actively work to end it.

We do not expect this argument to go down easily. So before proceeding we should clarify what we are and are not saying. We are not saying that ending R1 is the only—or even the most important—possible planning reform. Nor do we suggest that ending R1 will by itself solve the problems of segregation, exclusion, or housing affordability. Ending R1 is, like many reforms, necessary but not sufficient. R1 stands out for being both important and overlooked. Many reforms are proposed, debated, and (too often) defeated. R1, however, remains a third rail. Ending it is rarely on the table, but it should be. In the 21st century, no city should have any land where nothing can be built except a detached single-family home.

Because R1 is, in many places, an unquestioned status quo, we focus more on why planners should end it and less on how. We have no illusion that the politics will be simple or that every city can end R1 the same way. R1 may disappear through incremental reform rather than outright abolition. But the first step, no matter the subsequent path, is agreement that R1 should end. That is the case we make here.

A final clarification: We are arguing against a type of law, not a type of building. There is nothing intrinsically wrong with detached single-family homes. Two of the three of us live in them, and we all grew up in them. Living in a detached single-family home is a perfectly acceptable private choice, albeit one with real social and environmental costs (Arnold, Graesch, Ragazzini, & Ochs, Citation2012; Norman, MacLean, & Kennedy, Citation2006). But it is not a choice that warrants public protection. People in detached single-family homes neither need nor deserve laws ensuring that nothing will surround them but structures like their own.

The Case Against R1

Why do we oppose R1? Suppose that, for your wellbeing, you need regular access to only a small amount of expensive medicine. One day you go to the pharmacy and learn the government has implemented a new rationing system strictly limiting the number of sales that can occur in small doses. Because many people, like you, only need small doses, the new rule results in few small doses being available. Plenty of medicine is available—you can see it over the counter—but the pharmacist can only sell it in large quantities. So you are stuck. If you want your medicine, you must buy more than you need, at a price higher than you can afford. This new rationing system is also strictly enforced. Not only must you buy in large quantities, but you cannot divide up your ration afterward and sell your extra doses to others who might need and value them.

Most people, we suspect, would consider such a rationing system unjust and inefficient. It would force a large number of people to spend and consume more than they otherwise would, subsidize the smaller number of people who want and can afford large doses, and keep some people from getting medicine at all.

Fortunately, the United States does not allocate medicine in this bizarre manner. But it does ration urban land this way. And although land is not medicine, access to land, like access to medicine, has powerful implications for wellbeing. Where people live directly affects their exposure to pollution and violence (Chakraborty & Zandbergen, Citation2007; Peterson & Krivo, Citation2010), the quality of schools their children can attend (Reardon & Owens, Citation2014), and the jobs they can reach (Johnson, Citation2006). Residential location is thus strongly correlated with many life outcomes, from earnings to educational attainment to mental and physical health. Location, moreover, has not just large but multigenerational returns, yielding better outcomes for people who move in and their children as well (Chetty & Hendren, Citation2018a, Citation2018b; Currie, Citation2011).

Because opportunity is unevenly distributed both between and within metropolitan areas, and because moving people to opportunities is generally easier than moving opportunities to people, letting more people live in the most prosperous and amenity-rich neighborhoods of our urban areas would dramatically increase wellbeing (Chetty & Hendren, Citation2018a, Citation2018b; Lens, Citation2017; Sanbonmatsu et al., Citation2011; Sharkey, Citation2013). Many people, however, are effectively barred from these cities and neighborhoods because access to them is sold primarily in large, expensive, and inefficient chunks—through R1. Lower and middle-income families would benefit immensely from a small foothold in prosperous neighborhoods—perhaps a modest apartment or duplex—but R1’s prevalence means few such small footholds are available. The result is scarce housing in desirable places. This scarcity, in turn, pushes prices beyond what many can afford and burdens many others by forcing them to buy more housing than they need. The consequences are debt and stress as well as a growing anxiety among many families that they are running in place on the road to economic security (Frank, Citation2007; Warren Tyagi & Warren, Citation2004).

Just how much urban land is zoned R1? Estimates differ depending on one’s choice of denominator (all land, residential land, land with or without road space, etc.). But all are high, even in central cities. In San Francisco (CA), home to some of the most valuable and productive land on Earth, about 38% of residential land is R1. In Los Angeles (CA) the proportion is more than 70%. Seattle’s (WA) estimated share is more than 80%, and San Jose’s (CA) approaches 90%.¹ In the prosperous suburbs of urban areas, moreover, R1 approaches ubiquity (Hirt, Citation2014). The low-crime, high-job access, high–test score communities that ring cities around the United States are defined by their detached single-family homes, which in many cases are virtually the only housing zoning allows.

R1 arose, at least in part, from invidious motives. It was built on arguments about the sort of people who don’t live in detached single-family homes and the harms that would arise if they mixed, socially or as fellow taxpayers, with those who do. R1 first proliferated after the Supreme Court struck down racial zoning in Citation1917’s Buchanan v. Warley decision. Buchanan made single-family mandates appealing because they maintained racial segregation without racial language. Forcing consumers to buy land in bulk made it harder for lower income people, and therefore most non-White people, to enter affluent places. R1 let prices discriminate when laws could not (Trounstine, Citation2018; Weiss, Citation1987).

Contemporary observers denounced this regime of backdoor segregation, but in 1926 the Supreme Court upheld it. In Village of Euclid v. Ambler Realty Co. (Citation1926), the court tacitly excused R1’s implicit racism by validating its explicit classism.² Cities could prohibit apartments, the court said, because apartments were nuisances: “mere parasites” on the value and character of single-family homes. In Euclid’s wake, R1 became a quiet weapon of the White and wealthy in their campaign to live amid but not among the non-White and poor (Danielson, Citation1976; Rothstein, Citation2017; Trounstine, Citation2018).

Today’s planners cannot be blamed for R1’s origins; however, the past throws a long shadow over the system they now administer. R1 delivers large and undeniable benefits to some people who own property. In places where housing demand is high, R1 inflates home values and protects the physical character of neighborhoods. But its social costs exceed these private benefits. Higher property values for owners mean higher rents for tenants. Because homeowners as a group are richer and Whiter than renters, policies that increase housing prices redistribute resources upward, increasing homeowner wealth, reducing renter real incomes, and exacerbating racial wealth gaps.³ When cities prohibit development in amenity-rich neighborhoods, furthermore, housing demand does not disappear. It moves to other neighborhoods—where it may fuel gentrification and displacement—and into the urban fringe, resulting in longer commutes, greater emissions, and less open space.

These factors combine to make R1 the sort of problem planning was designed to solve. R1 is a classic collective action problem, an inefficiency that arises when people pursuing their own ends generate an outcome that harms the larger whole. It is also an affront to social justice, an impediment to a more inclusive and integrated society. Yet R1, with its dark past and present harms, is not an institution planners are trying to end. Instead it is an institution planners created, and one they too often work to protect. Even bold zoning reform usually steers clear of R1 (Monkkonen, Citation2019). Cities will consider more height and density, but almost always in places that are already tall and dense.

Planners and planning documents often talk about R1 neighborhoods the way conservationists talk about manatees. Zoning codes describe R1 in language that combines normative approval of single-family living with dark hints about looming threats (Hirt, Citation2014). Zoning codes in both Detroit (MI) and Milwaukee (WI) discuss “protecting” and “preserving” R1, after noting R1 is characterized by “high ratios of homeownership” and “suitable characteristics of family life” (Hirt, Citation2014, p. 58). An explicit priority in Los Angeles’s General Plan Framework Element is to “preserve single-family neighborhoods by focusing any growth away from them and into centers” (City of Los Angeles, Citationn.d.). In both 2018 and 2019, California’s legislature considered laws that would supersede local zoning and allow multifamily housing on all land near transit, including R1 zones. Los Angeles’s mayor objected both times, calling 2018’s law “too blunt for single family home areas” (Dillon & Zahniser, Citation2018) and 2019’s law “a bad stick” that would threaten neighborhood character (Cowan, Citation2019). The cake was taken, however, in 2018, when Seattle’s mayor bravely suggested ending R1 in her city. The Seattle Times editorialized against her in tones that would have done Euclid proud. “Seattle must preserve its single family neighborhoods,” the paper intoned, calling them the city’s “most precious asset” and “essential to its livability, character and economic success” (“Don’t Upzone Seattle Neighborhoods,” Citation2018).

The Nonexistent Case for R1

What makes R1 so important? The arguments in its favor are consistently weak. One common contention—made by journalists, neighborhood groups, and some academics—is that most Americans prefer detached single-family homes, and trying to change that preference is impossible (Kotkin & Cox, Citation2019; Swanson, Citation2015). This argument has two problems. First, it is not obvious that R1 is always a majority preference. Certainly many people live in R1 neighborhoods. But housing is a long-lived good, and because single-family homes are often all that zoning allows, the prevalence of single-family living might be partly an artifact of constrained choice. People’s preferences can influence zoning, but at least some evidence suggests zoning can influence preferences (Levine, Citation2005).

Second and more important, our goal is to end a mandate, not change a preference. R1 is not problematic because it allows detached single-family homes. It is problematic because it does not allow anything else. In places where housing demand is low and everyone wants a detached single-family home surrounded by detached single-family homes, most structures will be single-family homes, regardless of regulation. The zoning in this case does not bind. Nonbinding zoning imposes no costs but also delivers no benefits, so it is not clear why we need it. In other places, however, where housing is in high demand, R1 does bind: Neighborhoods would not be uniformly single-family without it. In these places R1 suppresses the supply and diversity of housing and denies some people access to the housing and opportunities they want. Put another way, where R1 is harmless, it is also unnecessary. But where it is necessary, it is also harmful. Both situations argue for its abolition.

A second argument for R1 is aesthetic: R1 protects against excessive density. This argument is most common among neighborhood groups and other incumbent residents (Dougherty, Citation2017). Anti-development advocates in Los Angeles, for example, often decry the “Manhattanization” (or, in one case, the “Dubai-ization” [Dillon, Citation2018]) of the city’s neighborhoods. Certainly it could be disconcerting to have a tower suddenly loom over your single-family home. But this is an argument against tall buildings, not for R1. Rejecting the most restrictive zoning need not require embracing the most permissive zoning. Cities can end R1 and allow structures other than single-family homes—townhouses, triplexes, and so on—without allowing skyscrapers.

Removing R1, in fact, could reduce rather than increase the prevalence of high-rise development. Tall buildings are at least partly a response to the scarcity of development-friendly parcels. When development can occur on only a small share of land, more pressure exists to build that land out intensively (and, as a consequence, more expensively). In cities where most residential land is R1, legalizing mid-rise development in single-family neighborhoods could dramatically increase the housing supply, at relatively low cost, with no high-rise development at all.

Aesthetics, at any rate, are often in the eye of the beholder. Certainly some people think detached single-family homes are the highest expression of urban design. But many others prefer the townhomes of Philadelphia (PA), the duplexes of New Orleans (LA), or the pleasant mix of building types that define Tokyo (Japan) and Mexico City (Mexico). To the extent the world has a consensus “beautiful” city, it might be Paris (France), which has almost no detached single-family homes (and, for that matter, almost no skyscrapers). Aesthetics matter, but R1 prevents some buildings many people consider attractive, does not prevent detached single-family homes that are unattractive, and most of all has high social costs unrelated to building appearance. Locking people out of opportunity is a high price to pay for consistency in lawns and gables.

The zoning language we quote above suggests another argument for R1: Detached single-family neighborhoods generate a special sort of social life (Hirt, Citation2014; McCabe, Citation2016). In this telling, which has echoes of the Euclid decision, R1 is synonymous with the American Dream, uniquely suitable for homeownership and raising families. Set aside for a moment the question of whether homeownership is something public policy should promote (e.g., McCabe, Citation2016). The idea that R1 neighborhoods are the only places families can thrive is supported by virtually no theory or evidence: It is a product mostly of rank classism. Every day, all over the world, people successfully raise children in and around townhomes, condos, and apartment buildings. Planning language that singles out R1 as family friendly implies that other areas are not and suggests that parents in other, less-expensive neighborhoods are somehow doing their children a disservice. The planning profession should abandon such condescension and elitism.

A fourth defense of R1 involves some form of “whataboutism.” Why focus on R1? What about funding more subsidized housing? Abolishing parking requirements? Reducing minimum lot sizes? What about all the other ways cities can exclude? These are legitimate questions. But our argument, again, is not that ending R1 solves every urban problem. We are no friends to minimum lot sizes or parking requirements, and America absolutely must fund subsidized housing more generously. Acknowledging that these reforms are necessary does not make ending R1 unnecessary. Indeed, without ending R1, the efficacy of these other reforms would be limited. Suppose the United States dramatically expanded housing vouchers. Poor renters would have more money but remain badly constrained in where they could spend it because R1 would still wall off large swathes of urban land. In this situation, where poor renters have more spending power for housing but not more housing choices, landlords can simply raise prices and pocket the vouchers as profit (Collinson & Ganong, Citation2018). Affordable housing policies will be far more powerful when more land is open to affordable housing development.⁴

It is true that R1 is not the only way cities can exclude. It is, however, the easiest and most prevalent way. Few weapons in the exclusionary arsenal rival a blanket prohibition on all but the lowest density development. The fact that cities can erect other barriers to housing is no excuse for leaving the biggest barrier intact. People sometimes commit violence with knives, but that is not an argument against gun control.

A final argument, which we take more seriously, is that ending R1 risks evicting tenants in single-family homes. When R1 is upzoned, single-family landlords can earn windfalls by selling to developers, but their renters could be put on the street in the process. Although this concern is valid, it is not a concern unique to upzoning R1: it is a concern about upzoning, period. If the presence of renters makes upzoning R1 problematic, then it must make upzoning multifamily neighborhoods even more problematic because multifamily neighborhoods have far more renters. By this logic, cities should not upzone any neighborhoods at all.

Anyone concerned about housing affordability, however, should favor upzoning, not oppose it. If cities worry upzoning will harm renters, then cities should upzone places where renters are least likely to live. This means upzoning R1. Most people in detached single-family homes are not renters, and most renters, especially low-income renters, are not in detached single-family homes. The American Housing Survey shows that in the metropolitan United States, only 10% of households in detached single-family homes are poor, compared with close to 30% of households in multifamily units. More than 60% of the poor households in single-family homes, moreover, own their dwellings. In total, only 4% of detached single-family homes in the United States hold renters whose household incomes are below $25,000 (U.S. Census Bureau, Citation2017).

These statistics do not mean, of course, that upzoning R1 will never displace tenants. But they do suggest the problem can be managed. Cities can and should attach strong renter protections to upzoning: They can require owners give tenants ample notice, generous buyouts, and even rights of return. Provisions like these will ensure that owners only benefit from their windfalls if they do right by their renters.

Homeowners will still receive windfalls from the upzoning, and this may seem unfair, but remember that homeowners also receive windfalls from not upzoning. When land is not upzoned, values rise because housing cannot be built. When land is upzoned, in contrast, values rises because housing can be built, and homeowners can only access that value when they sell to someone planning to build it. Accessing that value, moreover, makes it liquid. When homeowners sell, their windfall housing wealth becomes windfall income, and taxing income is easier, politically and administratively, than taxing wealth. If local governments pair upzoning with a progressive tax on real estate transfers, they can get more market-rate housing and more funding for subsidized affordable housing. The question, then, is not whether homeowners will receive windfalls. It is whether those windfalls will come from maintaining housing scarcity or enabling housing abundance.⁵

Conclusion: The Elephant in Planning’s Room

The American way of zoning is unique. Many countries privilege homeownership, and many households worldwide live in single-family homes. The United States is almost alone, however, in using regulation to promote and protect neighborhoods of detached single-family homes and to imply that life in these neighborhoods is synonymous with good citizenship and responsible family life (Hirt, Citation2014). This valorization of detached single-family living embeds a long line of prejudice and bias—against non-Whites, nontraditional families, the poor, immigrants, and urbanity—into local zoning. Planners have twin obligations to equity and efficiency, and R1 fails on both counts. America’s inefficient allocation of urban land creates unequal opportunities and unequal outcomes.

Zoning is important. By offering residents some assurance about the future of their communities, it can encourage people to invest both time and money in the places they live (Fischel, Citation2002). That is undoubtedly to the good. But certainty and stability are not sovereign virtues. Their benefits must be weighed against their costs, and those costs include the burdens carried by people who live outside strictly zoned areas. No one has an inviolate right to steadily appreciating property wealth, and reasonable certainty about the future is not the same as perpetual protection from all threats, real and imagined, that might come from new development.

One could accept our argument and still question its political feasibility. Perhaps we are just proposing a series of losing battles with neighborhood associations. We do not think so. Ending R1 will be difficult but not impossible. R1 can end neighborhood by neighborhood, city by city. Some cities might expand their use of zoning, like form-based codes, that eschews strict use restrictions. Others might permit more accessory dwellings. In expensive regions, even incremental progress will help. But progress could also come faster. Minneapolis’s (MN) 2019 General Plan includes a framework for ending R1, and Oregon’s governor has proposed similar legislation. The mayors of three large California cities have said they are open to ending R1 (Dillon, Citation2019). Maybe these efforts in Minneapolis and Oregon will sputter; maybe these mayors were being insincere. At least some signs, however, point to change.

Even if we are wrong, and the politics are more daunting than we think, that hardly constitutes license for inaction. Planners should not stand down in the face of a social harm, particularly a social harm that lies clearly in their domain, simply because reform is unpopular. Planners are public servants, but they can serve the public by leading as well as following. Single-family zoning is a status quo planners should work to change. Planning’s past already has too many instances where the profession stood on the sidelines, or on the wrong side, during fights for progress. R1 is without question planners’ responsibility. As others recognize its consequences, planners should at least help, if not lead, efforts to end it and to reverse the damage it has done.