We’ve talked a lot about zoning on this blog, but we wanted to include it in this series because it is such a crucial part of this conversation and of the solution to affordable homeownership. Zoning was created to safeguard communities. However, over the last century, it has become the most powerful tool for preventing the construction of affordable homes. A few cities are beginning to change this, and the data is already reflecting those shifts, proving that revised zoning actually works.
In the first two posts of this series, we identified what the housing crisis really consists of: flawed affordability criteria and a production gap in manufactured housing. Today, we will discuss a third obstacle: zoning, the legal framework of nearly every community in the United States that dictates housing, construction, and community livability.
The version of zoning that became dominant in American cities and suburbs after World War II is a system based on separating land uses, safeguarding single-family neighborhoods, and setting minimum standards for lot sizes and home square footage. In practice, this makes it difficult to build the types of housing that moderate-income and low-income households can actually afford. Understanding where this system originated, how it functions, and where it is being successfully reformed is crucial to figuring out what is needed to close the housing gap.
How the Rules Got Written
New York City enacted the first comprehensive zoning ordinance in the United States in 1916, motivated in part by legitimate public health and safety concerns, separating heavy industry from residential neighborhoods, managing building heights to allow sunlight to reach street level. The Supreme Court confirmed the constitutionality of municipal zoning in 1926 in the landmark case Euclid v. Ambler Realty Co., which upheld local governments’ authority to separate land uses into distinct zones.
Berkeley, California, implemented single-family-only zoning in the 1910s specifically to prevent Black and Asian residents from moving into white neighborhoods. St. Louis used zoning in 1918 to uphold racial separation after the Supreme Court declared explicit race-based zoning unconstitutional. This pattern was repeated nationwide: as courts invalidated openly racial ordinances, local governments replaced them with seemingly neutral rules, such as minimum lot sizes, minimum square footage requirements, and bans on multi-family housing, which produced the same exclusionary results. The Journal of Housing and Development reports that cities that adopted zoning early had racial segregation rates more than 25% higher by 1970 than similar cities that did not.
Today, local governments across the United States have their own zoning codes. For example, in Charlotte, North Carolina, 84% of residential land is zoned solely for single-family homes. In San Jose, California, 94% of residential land is zoned for single-family homes. This pattern is not due to geography or market preference by chance. It is the result of a century of intentional policy decisions, and it directly affects what can be built, where, and at what cost. The further extension of this is that it often dictates who can live where by restricting the factors that enable affordable housing for moderate- to low-income residents, such as reduced lot sizes, infill housing, or smaller-footprint housing.
What the Rules Actually Prevent
For this series, the most significant zoning restrictions are those that prevent small-footprint, owner-occupied infill housing from being economically viable. These include:
Minimum lot sizes that require a parcel to be at least 5,000, 7,500, or 10,000 square feet, much larger than what a 550–750 square foot home needs, effectively make infill affordable development on vacant urban lots illegal.
Minimum square footage requirements that mandate homes of 1,000, 1,200, or 1,400 square feet, regardless of household size or buyer preference, adding $50,000 to $100,000 or more to construction cost before a single design choice is made.
Single-family-only zoning that prohibits duplexes, triplexes, and small multifamily buildings on the majority of residential land in most American cities.
Parking minimums require one, two, or more off-street parking spaces per unit, adding $10,000 to $50,000 per space to construction costs and consuming land that could otherwise support additional housing.
Design standards that require architectural treatments, facade materials, or landscaping features calibrated to market-rate construction, adding cost to developments that cannot absorb it.
Taken individually, each restriction seems modest, and it is plausible that they are put in place to preserve a neighborhood’s character. Bundled together, and most zoning codes bundle them, they effectively price low-income housing out of existence. According to the National Association of Housing and Redevelopment Officials, bundled zoning reforms that address multiple issues simultaneously, such as minimum square footage, height restrictions, setback requirements, minimum lot sizes, and parking requirements, are far more effective than any single change alone. The reforms that have produced measurable results are those that tackled multiple barriers simultaneously.
What Reform Actually Looks Like
Several cities and countries have moved beyond discussion and into implementation. The results are documented and instructive.
Auckland, New Zealand — The Most Ambitious Reform in the World
In 2016, Auckland enacted the Auckland Unitary Plan, which revised the zoning for approximately three-quarters of the city’s residential land. Before the reform, roughly 95% of residential-zoned land in Auckland had restrictions equivalent to single-family-only zoning. The reform allowed up to three dwellings per parcel on most residential land, with higher density near transit.
The results, documented in peer-reviewed research published in Urban Studies and cited by HUD’s Cityscape journal, were significant. Building permits reached record highs in both total and per capita terms in the years following the reform. By February 2024, researchers estimated that Auckland’s housing stock had increased by approximately 80,000 dwellings, a 15% increase since the plan became active. In addition, the share of new home construction by government-controlled institutions also increased, from 3.1% in the decade before the reform to 9.9% afterward, indicating that upzoning benefited not just private developers but also publicly supported affordable housing providers.
Researchers describe the Auckland Unitary Plan as probably the most ambitious zoning reform in the world. The lesson it offers is not that reform is easy; it took years of political effort and faced significant opposition. It is that reform at scale produces results at scale.
Minneapolis, Minnesota — Bundled Reform, Measurable Outcomes
Minneapolis has pursued zoning reform in phases, and the evidence shows that bundling matters more than any single change. In 2015, the city legalized accessory dwelling units (ADUs), which we’ve previously blogged about. Also in 2015, it eliminated parking requirements near frequent transit service. In 2019, it adopted the Minneapolis 2040 Comprehensive Plan, which eliminated single-family-only zoning citywide, becoming the first major American city to take this step.
The results were remarkable, according to the Bipartisan Policy Center’s Minneapolis case study. Permits for two- to four-unit buildings increased by 45% between 2020 and 2022, driven largely by parking reform and ADU legalization, not by the elimination of single-family zoning alone. The number of housing units permitted in Minneapolis doubled from 2015 to 2020. Over 90% of new units were in larger buildings with at least 10 units.
These zoning changes significantly affected affordable housing. The Minneapolis Homes Financing program, which offers gap assistance to developers building affordable ownership homes, approved 230 units from 2021 to 2023. These units served households with incomes ranging from 30% to 80% of AMI, with an average buyer income around 60% AMI. Over 75% of buyers were BIPOC, and more than 50% of the program’s developers were BIPOC-led.
Cincinnati, Ohio — A Documented First-Year Result
Cincinnati’s Connected Communities zoning reform was implemented in mid-2024. The reform allows housing with up to four units in areas previously restricted to single-family homes near neighborhood business districts and along major transit routes. It also lowers or eliminates density limits and parking requirements for both residential and commercial developments.
Before Connected Communities took effect, Cincinnati’s ratio of building permits to zoning relief hearings stood at 13:1 in 2023. By 2024, the reform’s first partial year, it had decreased significantly, according to Deputy Director Emily Ahouse of the city’s Department of Planning and Engagement, who shared in an interview. Fewer hearings mean lower costs and faster timelines for developers. In other words, construction projects are moving forward with fewer hearings required. Fewer hearings mean lower costs, faster timelines, and more housing.
Oregon, Maine, Charlotte, Arlington — Single-Family Zoning Abolished
Between 2019 and 2023, the states of Oregon and Maine and the cities of Minneapolis, MN., Charlotte, N.C., and Arlington, Virginia, each passed laws to abolish single-family-only zoning, according to research published in Urban Studies. In January 2023, the City of Victoria in Canada passed its Missing Middle Housing Initiative, allowing up to six units on most residential lots and up to 12 units on corner lots citywide, all without requiring rezoning. The reform effectively ended single-family-only zoning in the city. These are not experiments. They are documented policy changes with stated goals of increasing housing supply and reducing costs, and they are producing data that will shape the next generation of reform.
What Reform Does and Doesn’t Do on Its Own
It would be misleading to present zoning reform as a complete solution. The research makes this point clear: eliminating single-family zoning alone does not ensure the creation of affordable housing. Minneapolis’s experience illustrates this directly: the removal of single-family-only zoning in 2019 produced only limited immediate results; it was the combined reforms that preceded parking elimination and ADU legalization that led to noticeable increases in permits.
Upzoning changes what is legally allowed. It does not change construction costs, access to financing, or land prices. In some cases, zoning reform can increase land values, which can, paradoxically, make development less financially feasible for the affordable housing producers who benefit most from reformed rules. Research published in Urban Studies on the Auckland experience confirms this dynamic: while the city’s overall housing stock grew substantially, effects varied across income levels and neighborhood types.
This is exactly why our series argues for an integrated model. Zoning reform is the necessary condition; it removes the legal prohibition on the homes we need. But without the production model in Post 2, the financing mechanisms upcoming in Post 5, and the permanent affordability structure upcoming in Post 4, zoning reform produces market-rate housing for higher-income households while the moderate-income gap persists.
For communities locally, the implication is specific: zoning codes that require minimum lot sizes of 7,500 square feet, minimum home sizes of 1,200 square feet, and two off-street parking spaces per unit are not neutral rules. They are active prohibitions on the 550- to 750-square-foot, owner-occupied, infill homes that households at 60–80% AMI can actually afford. Changing those rules does not build housing. But it clears the way for everything that does.
A century of zoning policies did not accidentally create the housing shortage. It was deliberately designed, initially as a tool for racial exclusion, then as a means of neighborhood preservation for those who could afford single-family homes, and now as a structural barrier so ingrained in local codes that most communities cannot or will not imagine an alternative.
Auckland imagined it. Minneapolis imagined it. Cincinnati is imagining it right now, and they are all measuring the results. The data from each of these cities tells the same story: when communities remove the legal prohibitions on the homes people need, those homes begin to get built.
Post 4, our next in this series, we will examine the mechanism that ensures those homes stay affordable not just for the first buyer, but for every buyer who comes after.
Sources
National Association of Hispanic Real Estate Professionals (NAHREP). “Zoning 101: Exclusionary Zoning as a Barrier to Housing Production.” October 2022. New York City 1916 zoning ordinance history. https://nahrep.org/nac/2022/10/12/nac-blog-zoning-101-exclusionary-zoning-as-a-barrier-to-housing-production/
National Association of Housing and Redevelopment Officials (NAHRO). “Rethinking Zoning to Increase Affordable Housing.” Euclid v. Ambler Realty Co. (1926). https://www.nahro.org/journal_article/rethinking-zoning-to-increase-affordable-housing/
Biden White House Council of Economic Advisers. 2024 Economic Report of the President, Chapter 4. St. Louis 1918 zoning history; Berkeley CA 1910s racial exclusion zoning; 30,000+ local governments with zoning rules. https://bidenwhitehouse.archives.gov/wp-content/uploads/2024/03/ERP-2024-CHAPTER-4.pdf
NAHRO. “Rethinking Zoning to Increase Affordable Housing.” Cities with early zoning adoption showed racial segregation rates more than 25% higher by 1970; racial segregation increased 50% during the 1900–1940 zoning adoption period. https://www.nahro.org/journal_article/rethinking-zoning-to-increase-affordable-housing/
Bipartisan Policy Center. “Eliminating Land-Use Barriers to Build More Affordable Homes.” Charlotte, NC: 84% of residential land zoned single-family; San Jose, CA: 94%. White homeownership rate 73.1% vs. Black homeownership rate 40.6%. https://bipartisanpolicy.org/article/eliminating-land-use-barriers-to-build-more-affordable-homes/
National Association of Home Builders (NAHB). “How Zoning Regulations Affect Affordable Housing.” November 2024. Single-family-only zoning history; California SB 9 and SB 10; Florida Live Local Act. https://www.nahb.org/blog/2024/11/zoning-regulation-and-affordable-housing
NAHRO. “Rethinking Zoning to Increase Affordable Housing.” Bundling of reforms — eliminating single-family zoning, amending height restrictions, minimum setback requirements, eliminating minimum floor area, and minimum lot size requirements — proves more effective than single-measure reform. Minneapolis parking elimination and ADU legalization drove permit increases. https://www.nahro.org/journal_article/rethinking-zoning-to-increase-affordable-housing/
Ka Shing Cheung et al. “The heterogeneous impacts of widespread upzoning: Lessons from Auckland, New Zealand.” Urban Studies, 2023. Published in final form 2024. Three-quarters of Auckland residential land upzoned; 80,000 additional dwellings (15% increase) by February 2024; described as probably the most ambitious zoning reform in the world. See also: HUD Cityscape, Vol. 26, No. 2. https://www.huduser.gov/portal/periodicals/cityscape/vol26num2/ch20.pdf
Ryan Greenaway-McGrevy et al. “Zoning reform and state-developed housing in Auckland.” Taylor & Francis Online, published April 2025. Government housing starts rose from 3.1% to 9.9% of total following the 2016 Auckland Unitary Plan.https://www.tandfonline.com/doi/full/10.1080/00779954.2025.2468710
Center for American Progress. “Building Opportunity: Expanding Housing in America by Reforming Local Land Use.” September 2024. Minneapolis 2019 comprehensive plan; 70% of city had been SF-only; parking elimination near transit 2015.https://www.americanprogress.org/article/building-opportunity-expanding-housing-in-america-by-reforming-local-land-use/
Georgia Journal of International and Comparative Law. “Land Use Zoning: The Answer to Housing Affordability? A Look at Auckland, New Zealand and Minneapolis, Minnesota.” Vol. 53, 2025. Minneapolis history of single-family zoning and reform timeline.https://georgia-international-journal.scholasticahq.com/article/154886-land-use-zoning-the-answer-to-housing-affordability-a-look-at-auckland-new-zealand-and-minneapolis-minnesota.pdf
NAHB. “How Zoning Regulations Affect Affordable Housing.” November 2024. Minneapolis: 45% increase in 2–4 unit permits from 2020 to 2022 following zoning and parking reforms.https://www.nahb.org/blog/2024/11/zoning-regulation-and-affordable-housing
City of Minneapolis. “The Way Home: Housing Policy Progress Report.” June 2024. 230 homeownership units approved 2021–2023; average buyer income approximately 60% AMI; over 75% of buyers BIPOC; over 50% of developers BIPOC-led; $11.5M in state funding leveraged.https://lims.minneapolismn.gov/Download/RCAV2/45545/The-Way-Home-Progress-Report-Update-June-4-2024.pdf
City of Cincinnati. “Connected Communities.” Approved by City Council June 5, 2024 (vote: 6–3); effective July 1, 2024. Led by Mayor Aftab Pureval. Allows up to four units in previously single-family areas near transit and business districts; reduces parking minimums.https://www.cincinnati-oh.gov/planning/connected-communities/ See also: WVXU. “City Council Approves Sweeping Zoning Reform.” June 5, 2024.https://www.wvxu.org/politics/2024-06-04/city-council-approves-sweeping-zoning-reform
WVXU. “Connected Communities Has Cut Regulatory Barriers for Construction, Report Says.” February 23, 2026. Building permits per zoning relief hearing: 13:1 in 2023, 14.2:1 in 2024, 16.3:1 in 2025. Statement from Deputy Director Emily Ahouse, Cincinnati Department of Planning and Engagement.https://www.wvxu.org/politics/2026-02-23/connected-communities-cut-regulatory-barriers-construction-report
Evaluating the Long-Run Effects of Zoning Reform on Urban Development. ScienceDirect / Urban Studies, 2024. Oregon, Maine, Minneapolis, Charlotte, Arlington abolished single-family zoning 2019–2023; Victoria, Canada upzoned 45% of lots to allow 6–12 dwellings per parcel (2023).https://www.sciencedirect.com/science/article/pii/S0166046224000930
