detached single-family homes other housing Residential land zoned for:

New York 15% Washington 36% Minneapolis 70% Los Angeles 75% Portland, Ore. 77% Seattle 81% Charlotte, N.C. 84% Sandy Springs, Ga. 85% Arlington, Tex. 89% San Jose, Calif. 94% Cities not shown to scale. Source: Zoning data for individual cities from UrbanFootprint

Single-family zoning is practically gospel in America, embraced by homeowners and local governments to protect neighborhoods of tidy houses from denser development nearby.

A reckoning with single-family zoning is necessary, they say, amid mounting crises over housing affordability, racial inequality and climate change. But take these laws away, many homeowners fear, and their property values and quality of life will suffer. The changes, opponents in Minneapolis have warned, amount to nothing less than an effort to “bulldoze” their neighborhoods.

Today the effect of single-family zoning is far-reaching: It is illegal on 75 percent of the residential land in many American cities to build anything other than a detached single-family home.

That figure is even higher in many suburbs and newer Sun Belt cities, according to an analysis The Upshot conducted with UrbanFootprint, software that maps and measures the impact of development and policy change on cities.

If this moment feels like a radical shift, said Sonia Hirt, a professor at the University of Georgia’s college of environment and design, it was also a radical shift a century ago when Americans began to imagine single-family zoning as possible, normal and desirable. That shift led Minneapolis to look like this:

Minneapolis

70% of residential land is zoned for detached single-family homes

Minneapolis Stripes of denser zoning running south from downtown follow historic streetcar routes. Bde Maka Ska Lake Harriet 1 MILE Minneapolis Stripes of denser zoning running south from downtown follow historic streetcar routes. Bde Maka Ska Lake Harriet 1 MILE Minneapolis Bde Maka Ska Lake Harriet 1 MILE

Minneapolis’s new policy will end single-family zoning on 70 percent of the city’s residential land, or 53 percent of all land. The Upshot used public zoning data compiled by UrbanFootprint to calculate this and draw similar maps for 10 other American cities.

Zoning codes vary significantly by city. But in each place, we sought to identify codes devoted to detached single-family homes, grouping rowhouses more common in older East Coast cities like Washington and New York into a second category covering all other housing types. (The earliest American zoning advocates clearly did not put rowhouses in the same category: A home, they believed, was a house “which one can drive a yoke of oxen around.”)

Many cities allow additional housing in nonresidential zones: for instance, in apartments built over offices or stores. These maps highlight the land exclusively set aside for housing.

Washington, D.C.

36% of residential land is zoned for detached single-family homes

In the predominantly white, upscale neighborhoods west of Rock Creek Park, 72% of residential land is zoned single-family. Rock Creek Park Washington D.C. 1 MILE About one-third of D.C.'s residential land is zoned for rowhomes, which predominate east of Rock Creek Park. About one-third of D.C.'s residential land is zoned for rowhomes, which predominate east of Rock Creek Park. Rock Creek Park Washington D.C. In the predominantly white, upscale neighborhoods west of Rock Creek Park, 72% of residential land is zoned single-family. 1 MILE About one-third of D.C.'s residential land is zoned for rowhomes. Rock Creek Park Washington D.C. In white, upscale neighborhoods west of Rock Creek Park, 72% of residential land is zoned single-family. 2 MILEs

Such maps reflect the belief that denser housing can be a nuisance to single-family neighborhoods just as a factory would be. That conviction is at least as old as the 1926 Supreme Court decision that upheld zoning in America.

Apartments, the court warned, block the sun and air. They bring noise and traffic. They act as a parasite on single-family neighborhoods — “until, finally, the residential character of the neighborhood and its desirability as a place of detached residences are utterly destroyed.”

Today, the very density that the court scorned is viewed by environmentalists as an antidote to sprawling development patterns that feed gridlock and auto emissions. It’s viewed by planners as an essential condition to support public transit, and by economists as the best means of making high-cost cities more affordable.

Single-family zoning “means that everything else is banned,” said Scott Wiener, a California state senator, speaking this spring at the Brookings Institution in Washington. “Apartment buildings — banned. Senior housing — banned. Low-income housing, which is only multi-unit — banned. Student housing — banned.”

Cities regularly “upzone” individual neighborhoods or properties to allow more housing options. Minneapolis’s remarkable approach was to upzone every single-family neighborhood at once. That was the fairest solution, officials argued.

“If we were going to pick and choose, the fight I think would have been even bloodier,” said Heather Worthington, director of long-range planning for the city.

New York City

15% of residential land is zoned for detached single-family homes

The Bronx 5% Manhattan 0% Queens 25% New york city New York’s famous 1916 zoning code did not include single-family zoning. It was first added to places like this in 1938. Brooklyn 3% Staten Island 22% The Bronx 5% Queens Manhattan 25% 0% New york city Brooklyn 3% Staten Island 4 MILEs 22% New York’s famous 1916 citywide zoning code did not include single-family zoning. It was first added to places like this in 1938. New York’s famous 1916 citywide zoning code did not include single-family zoning. It was first added to places like this in 1938. The Bronx 5% Manhattan Queens 0% 25% New york city Brooklyn 3% 4 MILEs Staten Island 22%

Even so, some residents vocally opposed the change, and the city collected 20,000 public comments on the broader plan that included the zoning proposal. The City Council ultimately voted for it, 12-1. If, as expected, a regional council approves it this year, duplexes and triplexes will be allowed citywide on what are now single-family lots.

The lesson of Minneapolis, said Salim Furth, an economist at the conservative Mercatus Center, is that a single, sweeping edit to these maps may be politically easier than block-by-block tweaking.

Over time, if just 5 percent of the largest single-family lots in Minneapolis — lots of at least 5,000 square feet — converted to triplexes, that would create about 6,200 new units of housing, according to UrbanFootprint. If 10 percent of similar-sized lots in San Jose, Calif., added a second unit, the city would gain 15,000 new homes.

“If you want to have the suburban American lifestyle, that will still be on offer,” Mr. Furth said. “What we’re really trying to change is that that has become so universal that there’s not much space left for anything else.”

A moment of crisis

While zoning remains invisible to many people, the problems it's connected to increasingly are not.

“Every community has to have a moment of crisis that eventually makes you pay attention to certain things,” said Taiwo Jaiyeoba, the planning director for Charlotte. “You knew they were there, but there was no impetus or motivation to address it.”

Charlotte, N.C.

84% of residential land is zoned for detached single-family homes

Neighborhoods north of downtown, near industrial land, have among the highest poverty rates and black population share in Charlotte. Charlotte 3 Miles Neighborhoods north of downtown, near industrial land, have among the highest poverty rates and black population share in Charlotte Charlotte 3 Miles Charlotte 3 Miles Note: Duplexes are allowed on corner lots in single-family zones.

The crisis struck in Charlotte in 2014, he said, when a national study ranked the region as having among the worst prospects in the country for poor children. Public meetings and task force reports followed, focused on Charlotte’s racial and economic segregation.

Zoning laws helped cement those patterns in cities across the country by separating housing types so that renters would be less likely to live among homeowners, or working-class families among affluent ones, or minority children near high-quality schools.

Mr. Jaiyeoba believed Charlotte had to change its zoning to become more equitable. But that argument seemed abstract until Minneapolis acted on it. This spring, Mr. Jaiyeoba invited Ms. Worthington to town to explain the idea in a public forum. Charlotte doesn’t have a formal proposal yet, but he hopes elected officials will lead the city toward one.

Ms. Warren, Mr. Booker and Mr. Castro, who have similarly emphasized racial inequality, have proposed leveraging federal money to nudge cities to change zoning laws.

San Jose, Calif.

94% of residential land is zoned for detached single-family homes

San Jose 3 MILEs The San Jose school district has proposed building teacher housing on school land here and elsewhere because of the city's affordable housing shortage. San Jose 3 MILEs The San Jose school district has proposed building teacher housing on school land here and elsewhere because of the city's affordable housing shortage. San Jose 3 MILEs Note: Area calculations do not include roads, sidewalks or railways.

On the West Coast, a severe housing shortage and environmental concerns loom larger. Single-family zoning leaves much land off-limits to new housing, forcing new supply into poorer, minority communities or onto undeveloped land outside of cities.

In California, a bill by Mr. Wiener affecting zoning statewide has been stalled by homeowners and local officials who object to state interference in their communities. The bill would allow more density around transit and jobs centers. It would also permit single-family homes to be subdivided into as many as four units, and multi-unit buildings to go up on vacant lots in single-family neighborhoods.

Los Angeles

75% of residential land is zoned for detached single-family homes

3 MILEs Los Angeles L.A. has invested heavily in transit, including a new light rail line here. But neighborhoods surrounding some stations remain zoned for single-family houses. Los Angeles 3 MILEs Los Angeles 6 MILEs

Oregon’s bill would allow options as dense as fourplexes across cities larger than 25,000 people and within metropolitan Portland, and it would permit duplexes in towns of at least 10,000. Portland has spent several years planning its own zoning changes to single-family neighborhoods, amid opposition by homeowners.

But the prospects for such ideas have improved from even two years ago.

Portland, Ore.

77% of residential land is zoned for detached single-family homes

The Laurelhurst neighborhood, which has long opposed denser housing, gained historic district status this year that will make change even less likely. Portland 3 MILEs The Laurelhurst neighborhood, which has long opposed denser housing, gained historic district status this year that will make change even less likely. Portland 3 MILEs Portland 3 MILEs Note: Duplexes are allowed on corner lots in single-family zones.

“Wages are up, people are working, unemployment is way down — and people can’t find a place to live,” said Tina Kotek, the speaker of the Oregon house and the author of the new bill. The dissonance between those facts, she said, is changing the politics of zoning.

The state has long regulated “urban growth boundaries” intended to protect farmland and green space beyond cities. But even so, many communities have been reluctant to grow denser inside those boundaries. In Oregon, the joke goes, people hate sprawl and density.

“At some point,” Ms. Kotek said, “something’s got to give.”

A return to history

High-level arguments about the environment, affordable housing or equity invariably meet more prosaic objections: What if some neighborhoods lack enough parking? Or if one person’s development shades another’s backyard? How are apartment buildings more environmentally friendly if they replace all the trees?

“What we’re selling here in Minneapolis — or what our planning department and our city council are selling — is that we’re new, we’re state of the art, we’re cutting-edge, we’re virtue signaling,” said Lisa McDonald, a former Minneapolis City Council member and part of a group opposing the city’s plans.

In reality, she said, Minneapolis is giving itself away to developers. They’ll build more market-rate housing, she said. But she doubts the city will get much more affordable housing — or less racism, more equity or a fairer society. Beware those promises, she warns other cities.

Seattle

81% of residential land is zoned for detached single-family homes

Seattle Neighborhoods like Wallingford were downzoned to single-family but still contain many multi-family buildings built in the early 20th century. 1 MILE Seattle 1 MILE Note: Most city parks and schools are zoned as single-family residential.

People elsewhere say their legitimate fears about traffic or the environment have been mischaracterized, caught up in an emotional debate over race and fairness. Martin Henry Kaplan, an architect in Seattle whose neighborhood association sued to block looser regulations on “accessory dwelling units,” recalled as a child that his parents couldn’t buy a house in a neighborhood where Jews weren’t welcome.

“I’m old enough to actually have lived in some of that,” said Mr. Kaplan, who is 70. But he does not see bigotry behind the objections to upzoning today. “Maybe I’m wrong, but I’ve grown up here, I have tons of friends in every neighborhood across the city, and I don’t get the sense that anybody thinks like that.”

Policies originally conceived in part to be exclusionary, he said, can still be useful toward nonexclusionary ends, like ensuring that neighborhoods don’t have more residents than their sewers can handle, or that families who sink their savings into a home know what to expect around it.

“Zoning has a role,” Mr. Kaplan said, “in addressing land-use regulations for the common good.”

This debate is partly about the scale of that common good, given that the common good desired within many single-family neighborhoods conflicts with the common good across whole cities where housing is scarce or segregated. In an uneasy compromise between those interests, Seattle in March upzoned 6 percent of its single-family land.

Chicago

79% of residential land is zoned for detached single-family homes

Chicago aldermen wield unusual power over the zoning of individual developments and blocks, producing a zoning patchwork in many areas. Chicago 3 MILEs Chicago 3 MILEs Chicago 3 MILEs

Cities have typically prioritized single-family homeowners above other groups, with the old belief that dense housing hurts their property values, said Andrew Whittemore, a professor of city and regional planning at the University of North Carolina-Chapel Hill. Evidence supporting that belief is mixed, but Mr. Whittemore suggests it’s the wrong thing to focus on.

“Why is it the job of a government to see that a housing unit accumulates as much value as possible?” he said. “I think the purpose of zoning is to prevent harm. Planners shouldn’t be wealth managers. But they effectively are in every municipality in the country.”

That is particularly true in more suburban communities where a higher share of land is devoted to housing, and a higher share of that housing is required to be single-family.

Sandy Springs, Ga.

85% of residential land is zoned for detached single-family homes

Much of this Atlanta suburb developed starting in the 1960s, well after single-family zoning became a norm nationwide. RT 400 Denser housing here is clustered along Georgia State Route 400. Sandy Springs 1.5 MILEs Much of this Atlanta suburb developed starting in the 1960s, well after single-family zoning became a norm nationwide. RT 400 RT 400 Denser housing here is clustered along Georgia State Route 400. Sandy Springs 1.5 MILEs Much of this Atlanta suburb developed starting in the 1960s, well after single-family zoning became a norm nationwide. RT 400 Denser housing here is clustered along Georgia State Route 400. Sandy Springs 3 MILEs

Citywide proposals to change these maps are not as unprecedented as they appear today. In 1960, Los Angeles had the zoned capacity for about 10 million people, according to Greg Morrow at the University of California, Berkeley. By 1990, Los Angeles had downzoned to a capacity of about 3.9 million, a number that is only slightly higher today. As a result, the city’s actual population is now uncomfortably close to what it legally has room for; residents of Los Angeles today effectively fill about 93 percent of the city’s zoned capacity, by Mr. Morrow’s calculation.

Arlington, Tex.

89% of residential land is zoned for detached single-family homes

The University of Texas at Arlington is here, surrounded by denser housing. Arlington 1.5 MILEs The University of Texas at Arlington is here, surrounded by denser housing. Arlington 2 MILEs

Advocates who want to curb single-family zoning, he said, are not pushing an idea that has never been tried before. They’re lobbying for a return to the past.

Many Minneapolis blocks today date to before the 1920s, with duplexes or small apartment buildings next to single-family homes. For years, those older buildings have been considered “nonconforming,” as the law changed around them. Under Minneapolis’s new plan, that distinction will end, too.