Zoning Reform and the YIMBY Movement

Zoning reform means changing local land-use rules so that more homes, and more kinds of homes, can legally be built. The YIMBY movement, short for “yes in my backyard,” is the loose coalition of residents, advocates and lawmakers pushing for those changes. Its central claim is that many communities have a housing shortage partly because their own rules make new housing illegal or slow to approve.

Since 2019 the idea has moved from city halls to statehouses. Minneapolis rewrote its own plan, and Oregon, California, Washington, Montana and Texas have passed state laws that override parts of local zoning. The early evidence suggests that reform does add homes, but gradually, and that allowing apartments and cutting parking mandates has produced more housing than legalizing duplexes alone. Critics question how affordable the new homes will be and who should get to decide what is built.

How Zoning Came to Limit Housing

Zoning sorts land into districts and sets what can be built in each. The Supreme Court upheld the practice in 1926 in Village of Euclid v. Ambler Realty Co., a case from an Ohio suburb.

Over the following decades, single-family zoning became the most common category of residential land in many American cities. Before Minneapolis changed its rules, single-family zones covered about 70% of the city, according to the Lincoln Institute of Land Policy. When such rules keep lower-cost housing out of a community, they are often called exclusionary zoning.

Land use is generally a state power, and many states have delegated it to local governments. The federal government has no direct authority over local land-use rules, the Congressional Research Service (CRS) notes. That is why the largest recent changes have come from state legislatures.

Common reform tools include:

• Upzoning, which raises the number of homes or the building size a lot may hold.
• Legalizing missing middle housing, such as duplexes, triplexes and townhouses, and accessory dwelling units on lots zoned for one house.
• By-right approval, in which staff approve projects that meet written standards without a public hearing or a discretionary vote.
• Cutting parking minimums, the rules that require a set number of off-street spaces per home.
• Lowering minimum lot sizes so that smaller, cheaper lots can be created.
• Allowing housing in commercial zones and near transit.

Where the YIMBY Movement Came From

Opposition to nearby development has long been labeled NIMBY, for “not in my backyard.” YIMBY reverses the phrase. YIMBY Action, one of the movement’s national organizations, says it began as a group advocating for housing in San Francisco and now has chapters across the country. Its members attend local hearings, write to officials and campaign for candidates. The group says it supports both market-rate and government-subsidized housing.

The movement does not follow the usual party lines. Oregon’s land-use agency describes that state’s 2019 law as bipartisan. Montana’s 2023 laws came from a governor’s housing task force and passed a Republican-controlled Legislature with bipartisan support, according to Montana Free Press. In Minneapolis, supporters framed reform as a matter of racial equity. City planners there tied single-family zoning to the history of racially restrictive covenants. The Lincoln Institute reported that many in the city credited outreach by officials and local YIMBY groups for the plan’s passage.

The Landmark Laws

Minneapolis 2040

Minneapolis 2040 is a comprehensive plan, the long-range document that guides a city’s zoning. The City Council voted in December 2018 to send the plan to the regional Metropolitan Council for review and finalized it in October 2019. Its policies took effect on January 1, 2020. The plan allows up to three homes on an individual lot in neighborhood interiors. The Lincoln Institute called Minneapolis the first major U.S. city to end single-family-only zoning in every neighborhood.

The plan spent years in court. A lawsuit filed in 2018 under the Minnesota Environmental Rights Act argued that building out the plan would harm the environment, and a district court ordered the city to stop carrying out the plan’s residential portions. The Minnesota Court of Appeals reversed that injunction on May 13, 2024. The Legislature also acted in 2024, declaring that comprehensive plans adopted by the largest Twin Cities-area cities do not count as environmental harm under that act.

Oregon House Bill 2001

Under Oregon’s 2019 law, medium-sized cities, which the state defines as those with 10,000 to 25,000 residents outside the Portland area, had to allow duplexes on single-family lots by June 30, 2021. Cities over 25,000 and cities in the Portland metro region had to allow duplexes, triplexes, fourplexes, cottage clusters and townhouses in residential areas by June 30, 2022.

California Senate Bill 9

Senate Bill 9, signed on September 16, 2021, requires cities to approve two homes on a lot in a single-family zone “ministerially,” meaning staff check the plans against objective standards. It also requires approval of a split of that lot into two parcels of at least 1,200 square feet each. The law does not apply where a project would demolish rent-restricted housing or housing a tenant occupied in the previous three years. An owner who splits a lot must sign an affidavit of intent to live in one of the homes for three years.

A 2024 amendment, Senate Bill 450, gives cities 60 days to act on an application and bars standards that do not apply uniformly within the zone. It also added a legislative finding that the housing shortage is a statewide concern, so that the law applies to all cities.

Cities have challenged the law in court with mixed results. In April 2024 a Los Angeles County judge ruled Senate Bill 9 unconstitutional as applied to five charter cities, which have added home-rule powers under the state constitution. KQED reported that the ruling covers only those five cities. In September 2025 a state appeals court rejected a separate challenge brought by four general law cities.

Montana’s 2023 laws

Montana’s package requires cities of at least 5,000 residents to allow a duplex wherever a single-family house is permitted. It also requires cities to allow accessory dwelling units, allows apartment buildings in commercial zones served by city water and sewer, and creates the Montana Land Use Planning Act.

A homeowners’ group, Montanans Against Irresponsible Densification, sued in late 2023. A district judge temporarily blocked two of the laws, and the Montana Supreme Court lifted that order in September 2024. In March 2026 the court unanimously rejected the group’s constitutional claims, Montana Free Press reported. The ruling reversed a lower-court finding that the planning act’s limits on public comment violated the state constitution’s right to participate in government. A 2025 amendment that took effect October 1, 2026, also caps the parking that city zoning can require, generally at one space per home.

The newer wave

Recent laws reach beyond duplexes. Texas Senate Bill 840 requires cities of more than 150,000 people in large counties to allow apartments in zones that already permit offices, retail or warehouses, with staff-level approval. Senate Bill 15 bars those cities from requiring lots larger than 3,000 square feet in new subdivisions on unplatted tracts of five acres or more. Both took effect September 1, 2025. California’s Senate Bill 79, signed in October 2025, makes developments of five or more homes an allowed use within a half mile of qualifying rail and rapid-bus stops. It covers stops in “urban transit counties,” defined as counties with more than 15 passenger rail stations. The law began applying to cities on July 1, 2026, lets them adopt state-approved alternative plans, and reaches unincorporated county areas later.

What the Early Evidence Shows

The evidence is recent, and most of it describes what happened after a reform without proving the reform caused it.

• Minneapolis. Pew found that the city permitted nearly 21,000 homes from 2017 to 2022, an estimated 87% of them in buildings with 20 or more units and 1% in two- to four-unit buildings. Over the same years the city’s housing stock grew 12% and rents rose 1%, while the rest of Minnesota added 4% to its stock and saw rents rise 14%. Pew credits corridor upzoning and the end of parking mandates more than the triplex rule, and notes that the period includes years before the 2040 plan took effect.
• Portland. The city reports permitting more than 1,400 accessory and middle housing units in single-dwelling zones between August 1, 2021, and June 30, 2024. In 2023–24, a new market-rate middle housing unit sold for $250,000 to $300,000 less, on average, than a new detached house.
• California. The Terner Center’s review of 13 cities found little use of Senate Bill 9 in 2022. Los Angeles received 211 applications for new units and 28 for lot splits, and most other cities received fewer than 10 of each. The authors pointed to construction costs, added local rules, the owner-occupancy requirement and the easier path of building an accessory unit.
• Across cities. An Urban Institute study of reforms from 2000 to 2019 found that loosening restrictions was associated with a 0.8% increase in housing supply within three to nine years. The gain was mostly in higher-rent units, with no statistically significant change in lower-cost ones. Reforms that tightened restrictions were associated with higher median rents.

Researchers at New York University’s Furman Center revisited the question in a 2025 paper and summarized their earlier review in two parts. Theory and evidence support the claim that more supply lowers prices and rents or slows their growth. The effects can be slow, however, and they are unlikely to be enough for very low-income households.

The Critiques

• Local control and process. Opponents such as the Montana plaintiffs and the California cities that sued over Senate Bill 9 argue that states are overriding local decisions and that by-right approval removes the public’s chance to object to a specific project. The Minneapolis plaintiffs sought an environmental review of that city’s plan.
• Affordability. Homes built under these laws are almost always market-rate housing. Skeptics note that the measured supply gains have been small and concentrated at higher rents.
• Displacement. Some observers worry that allowing more housing will raise nearby rents and push out current residents, a concern tied to gentrification and displacement. Pew reads the research as showing that more multifamily construction is associated with lower displacement risk. Some laws add guardrails: California’s protects tenant-occupied housing, and Washington’s lets cities seek extensions for areas at risk of displacement.
• Too modest. Some housing researchers say the first laws were too limited to change much. Pew notes that Minneapolis kept low floor-area limits and a 2.5-story height cap in its lowest-density zones, which makes triplexes hard to build.

The Federal Role

Federal law leaves zoning to states and localities, but Congress has begun to add incentives. The 21st Century ROAD to Housing Act, Public Law 119-101, became law on July 11, 2026. According to CRS, it:

• requires HUD to publish guidelines and best practices on state and local zoning by July 11, 2029
• authorizes an Innovation Fund of $200 million a year for fiscal years 2027 through 2031 for local governments and tribes that show improved housing supply growth
• adjusts some Community Development Block Grant allocations beginning in fiscal year 2029 based on local housing growth

CRS notes that the act contains no appropriations, so the grant programs depend on future funding.

What It Means for Workforce Housing

Workforce housing usually refers to homes for households earning roughly 60% or 80% up to 120% of area median income. Most federal subsidy programs stop at 60% or 80% of that income, so many of these households depend on what the private market builds. Zoning reform targets that market by lowering the land cost built into each home.

Suppose land in a neighborhood sells for $20 per square foot. A house on a required 7,500-square-foot lot carries $150,000 of land cost. A house on a 3,000-square-foot lot carries $60,000. (These numbers are invented for illustration.) That arithmetic is why small-lot and middle housing rules are often described as a route back to the starter home.

Lower prices are not guaranteed, because new homes sell or rent at market rates unless a program restricts them. Washington’s law links the two goals by allowing extra homes on a lot when some are kept affordable for at least 50 years under a recorded covenant. See Inclusionary Zoning, Explained for a related local tool and Missing Middle Housing, Explained for the housing types involved.

The Bottom Line

Zoning reform has moved from one city’s plan in 2018 to state law in Oregon, California, Washington, Montana and Texas, and appellate courts in Minnesota and Montana have let the changes stand. The early evidence shows that legalizing duplexes alone produces few homes, while allowing apartments and removing parking mandates has added more. The new homes are mostly market-rate, which can help middle-income workers over time. Zoning reform does not replace the subsidies that lower-income households need.