# M. Nolan Gray's Arbitrary Lines explained: the case for abolishing zoning, and what Spain can use

> Arbitrary Lines: How Zoning Broke the American City and How to Fix It (Island Press, 2022) is M. Nolan Gray's case for abolishing zoning. He argues that rules on land use and density raise housing costs, push workers out of productive cities, entrench racial and class segregation and force sprawl, and he points to Houston and Japan's simple national system as alternatives. For Spain, radical centrism takes his attack on rules that ban homes and his call to decide at a larger scale, and keeps public planning of infrastructure and narrow rules aimed at real nuisances.

- URL: https://www.radicalcentre.eu/en/articles/nolan-gray-arbitrary-lines-explained
- Language: en
- Publisher: radical centre / centro radical
- Published: 2026-10-26
- Topic: Ideas & history
- Author: radical centre
- Licence: CC BY 4.0

## Key points

- M. Nolan Gray is a city planner who worked in New York City; Arbitrary Lines came out with Island Press in 2022.
- He argues zoning raises housing costs, holds back productive cities, entrenches segregation and forces car-dependent sprawl.
- His reforms start with ending single-family-only districts, parking minimums and minimum lot sizes, with states reining in local exclusion.
- His long-term goal is abolition, with Houston as proof a big city can work without citywide zoning and Japan's twelve national districts as a simpler model.
- Critics point out that Houston's deed restrictions recreate exclusive enclaves and that the political path to abolition is hard.

M. Nolan Gray wants to get rid of zoning. *Arbitrary Lines: How Zoning Broke the American City and How to Fix It* came out with Island Press in 2022, and it is the most readable case anyone has made for abolishing the rules that decide what may be built where on private land. Gray worked as a city planner in New York and wrote the book while finishing a doctorate in urban planning at UCLA, so this is a planner arguing against his own profession's favourite tool. Our programme lists it as more radical than most centrist housing policy, and valuable for exactly that reason. Here is what he says, and how far radical centrism goes with him in Spain.

## What zoning is, and where it came from

Gray starts by clearing up what zoning actually does. As Kirkus summarises it, zoning governs the uses and densities allowed on private property, and it mostly prohibits things. The first ordinances arrived in 1916, in New York City and in Berkeley, California. The stated aims were reasonable enough: keep the slaughterhouse away from the school, and put dense building where the pipes and roads can carry it.

Gray reads the history differently. In his account, urban elites, later encouraged by the federal government, adopted zoning to exclude people and protect property values, and to make the detached single-family house the norm. Kirkus notes his claim that New York's earliest rules were aimed at keeping Eastern European Jews away from Fifth Avenue. Once explicit racial covenants became unacceptable, he argues, technical standards took over the same job: setbacks, floor area ratios, minimum room sizes. Apartments are the main target, because people associate them with poorer households, immigrants and minorities.

## Four charges

The middle of the book is a charge sheet. First, cost. Rules like minimum lot sizes and parking requirements cap supply, and where demand grows prices follow; many cities ban the cheapest options outright, like single-room occupancy buildings and manufactured homes. Second, growth. Borrowing from Alain Bertaud's view of the city as a labour market, Gray argues that restrictive rules push workers out of the most productive, expensive cities, and the UNC Charlotte Urban Institute's review reports his estimate that this has cost the country trillions of dollars. Third, segregation: zoning keeps doing the exclusionary job it was built for. Fourth, sprawl, because separating uses and capping density assumes everyone drives.

Santi Ruiz, reviewing it for the *Washington Free Beacon*, adds a detail worth keeping. Gray traces the "homevoter" to 1970s inflation and tax policy, which turned the family home into an investment and gave owners a direct stake in blocking new building nearby.

## How to fix it

Gray's programme has two stages. The first is making zoning less bad. End single-family-only districts, which the Charlotte review says cover over 75% of most US cities. Drop minimum parking, minimum lot sizes and minimum floor areas, and legalise the cheapest housing types. Have state governments limit how far local councils can use zoning to build exclusive enclaves. He admires Japan, where the national government sets twelve zoning districts and none of them is reserved for detached houses.

The second stage is abolition. "We can't tinker our way out of this one," he writes. His proof that a big city can live without zoning is Houston, which has never adopted it citywide and whose housing supply has kept up with demand. Houston's wealthier neighbourhoods protect themselves with private deed restrictions, and Gray presents that bargain as a model that could make abolition easier to sell elsewhere.

Gray is clear that planning survives. He wants planners to lay out street grids, parks and infrastructure, as earlier generations of planners did, and to regulate activities that genuinely disturb neighbours, using tools that target the noise or the fumes directly.

The reviews are mostly warm, with some useful objections. The Charlotte reviewer points out that Houston's deed-restricted neighbourhoods look a lot like the exclusive enclaves the book criticises; Gray accepts them because they cover far less ground. Ruiz thinks Gray narrows his argument to keep a broad coalition and leaves out the generational case and the family-formation case. H. Shelton Weeks, in *The Daily Economy*, stresses the politics: challenging a zoning decision is slow, costly and uncertain, and resistance to reform will be fierce.

## Where radical centrism goes with him, and where it stops

In Spain, municipal general plans do the job zoning does in America: they fix uses, densities and buildable floor space plot by plot. Madrid's Plan Reside shows both sides of Gray's argument in one document. It amends 19 articles of the city's 1997 general plan and took effect on 22 September 2025, according to the legal publisher Sepin. It lets office buildings become housing, with extra buildable floor area as an incentive. It also forbids turning ground-floor shops into homes on the main commercial streets of the historic centre and on certain commercial streets elsewhere. A Gray reader asks of that second rule what harm a family living in a former shop actually causes.

The Bank of Spain is asking a similar question at a larger scale. Its 2025 annual report, as Alimarket reported, says that raising densities on land already being developed to the level of consolidated city centres could add up to 1.2 million homes in Madrid, Barcelona, Málaga, Valencia, Zaragoza and Seville.

So we take a lot from Gray. From the left tradition, his evidence that land-use rules have been a machine for sorting people by race and class, which makes opening expensive neighbourhoods a question of fairness, alongside the public role in streets, transport and social housing that he himself keeps. From the market-liberal tradition, the plain case for letting owners build flats, small homes and cheap housing types where people want to live. And from neither, a way of governing land that protects what zoning promised to protect with narrow rules aimed at real effects, such as noise, emissions, traffic and the load on local infrastructure, written at a scale where future residents count. That last part is Gray's state oversight and Japan's national menu, and it fits Spain well: regions and the state can set a short list of permitted uses and minimum densities that councils cannot shrink.

We stop at full abolition and at the Houston bargain. Private deed restrictions hand exclusion back to whoever can afford a covenant, and Spanish cities need a public authority that urbanises land and builds the trunk infrastructure, as our piece on [developable land](/en/articles/developable-land-spain-why-it-does-not-get-developed) argues. Gray's book is the sharpest tool on the shelf for spotting which lines on the plan are arbitrary. Read it next to [Bertaud](/en/articles/alain-bertaud-order-without-design-explained) and [Jerusalem Demsas](/en/articles/jerusalem-demsas-on-the-housing-crisis-explained), and the week's argument about who decides gets much clearer.

## FAQ

### What is Arbitrary Lines about?

It is a 2022 Island Press book by the planner M. Nolan Gray. It tells the history of American zoning, sets out four harms (housing costs, lost growth, segregation and sprawl) and argues that cities should first loosen zoning and eventually abolish it.

### Does Nolan Gray want to abolish planning?

No. He attacks zoning, the separation of land uses and the control of density on private land. He wants planners to go back to laying out streets, parks and infrastructure, and to regulate activities that actually disturb neighbours.

### Why does Gray talk about Houston?

Houston has no citywide zoning, and Gray uses it to show that a large city can grow and keep housing supply in line with demand without it. Wealthier neighbourhoods there protect themselves with private deed restrictions, a compromise he thinks could make abolition easier to sell elsewhere.

### Does Spain have zoning like the United States?

Spain regulates land through municipal general plans that set uses, densities and buildable floor space, so many of Gray's questions apply. Madrid's Plan Reside, in force since September 2025, both eases office-to-home conversions and bans turning shops into homes on certain streets.

## Sources

- ['Arbitrary Lines' and the case for killing zoning](https://ui.charlotte.edu/?p=35381), UNC Charlotte Urban Institute (2022)
- [Arbitrary Lines (review)](https://kirkusreviews.com/book-reviews/m-nolan-gray/arbitrary-lines-zoning/print), Kirkus Reviews (2022)
- [Zones of Conflict](https://freebeacon.com/policy/zones-of-conflict/), Washington Free Beacon (Santi Ruiz) (2022)
- [A Review of M. Nolan Gray's Arbitrary Lines](https://thedailyeconomy.org/article/a-review-of-m-nolan-grays-arbitrary-lines-how-zoning-broke-the-american-city-and-how-to-fix-it/), The Daily Economy (H. Shelton Weeks) (2023)
- [Medidas sobre viviendas turísticas en Madrid: Plan Reside 2025](https://blog.sepin.es/blog/2025/10/08/medidas-viviendas-turisticas-madrid-plan-reside-2025/), Sepin (2025)
- [El Banco de España pide cambiar los planes urbanísticos y densificar el suelo para sumar 1,2 M de viviendas](https://www.alimarket.es/construccion/noticia/427996/el-banco-de-espana-pide-cambiar-los-planes-urbanisticos-y-densificar-el-suelo-para-sumar-1-2-m-de-viviendas), Alimarket (2026)