In one of her several lightning-rod analyses on housing, Jerusalem Demsas, a staff writer at The Atlantic, contributed a piece last Fall that editors entitled, "Housing Breaks People's Brains."

The heart of why that's the case is ordinary people, neighbors mostly. And the power and tendency of local zoning to cudgel so many initiatives to add housing attainable to new-comers, lower-wage earners, and those in need of supportive living solutions.

And what local zoning is definitionally is a black box unto itself, one for every one of 30,000 or so local governments in the U.S. with zoning laws. They're responsible for two of the three "locations" in one of real estate's cardinal designations for value everywhere and for all of time: Location, location, location. One of them applies to a jurisdiction and another of the three traces to people – i.e. neighbors – who own the land within the jurisdiction's border lines, and their "say," or political will, in what ever happens next there.

After all is said and done, however, as currently "unrelated" as America's local jurisdictional zoning laws are to one another, they're susceptible to being looked at relationally. Teams of people – powered by machine learning and geospatial information – are able to dissect zoning laws in each location, unpacking the "yesses and nos" and the "stops and goes," and filter them into "1s and 0s," the language of computers.

It begs a big big question:

If the U.S.'s 30,000 localities with their own bespoke zoning ordinances were able to be transformed from a teeming ocean of discrete local belief systems into a coherent knowledge base of relational data, characteristics, and impacts on local economics, safety, health, quality of life, housing access, community sustainability, and other values how might that alter things?

Would the knowledge impact policy, community advocacy, economic diversity, and trajectories of risk or resiliency?

Evidence suggests a U.S. zoning single-source-of-truth could lead local, regional, and state stakeholders to new and different opportunity areas, both from a recognition of comparative zoning practices and their ties to economic and resiliency outcomes.

Team members driving 2023 Ivory Prize-winner National Zoning Atlas, an ambitious six-year blitz to log every one of the United States' localities for their zoning codes – culling around 100 characteristics from 150-page documents that spell out local ordinances, and ingesting them into a single relational knowledge base – believe a completed project, expected in 2028 or so, would ignite change to:

• Support evidence-based policymaking and fuel advocacy at the local, state, and federal levels
• Strengthen planning for housing production, transportation infrastructure, economic growth, and climate response

Here's a few examples from real-life:

• In Connecticut, advocates used the Atlas’s findings to justify the state’s landmark 2021 law that made the first reforms to statewide zoning laws in over 30 years
• In Montana, the Atlas has aided the Frontier Institute advocacy team to introduce more housing-related bills in legislation than ever before.
• The Atlas is being used in New York to study sea level rise which will provide proof of zoning that is in danger of flooding.

We talked today with Sara Bronin, director of the National Zoning Atlas, Connecticut Zoning Atlas, and Professor and Director of the Legal Constructs Lab at Cornell University. Sara has been the force driving this effort forward. In late December 2022, Bronin was confirmed by unanimous vote as chairman of the Advisory Council on Historic Preservation (ACHP) following her nomination by President Joe Biden.

Bronin and her team recently completed a version 2 "how to" guide as a baseline template for their enormous effort. Their current efforts lay out as follows:

• 25 state teams—including state agencies, local officials, private firms, university researchers, and nonprofits—produce state-specific zoning atlases.
• On average, these efforts have a timeline of 3-18 months from inception to completion, depending on the complexity of the state’s zoning landscape.
• Their in-progress research covers approximately 25% of US jurisdictions with zoning. To ensure their research can be harmonized within the national map and to expand the number of jurisdictions covered, the Legal Constructs Lab must build up its central intake and data collection team.
• Their goal is to have the National Atlas completed in 5 years.
• Within the National Zoning Atlas greater research collaborative, researchers from various institutions explore the relationship between regulation and the built environment and spatial manifestations of data

Here's a curated account of our conversation with Sara Bronin, on motivations, expectations, what builders, developers, and investors need to know, what it means, and why it matters in the context of housing affordability, sustainability, and resiliency.

Why A Single-Source-of-Truth For Zoning?

Sara Bronin

We started the Connecticut Zoning Atlas in response to inquiries that we received after starting the DesegregateCT advocacy movement. We realized that we needed to make sense of how zoning actually worked in the state's 169 municipalities, but found that there was not enough information to do so  because you couldn't really make apples-to-apples comparisons from one jurisdiction to another because of the way that zoning codes are written and adopted independently.

We started collecting information just about whether the jurisdiction allowed one-family, two-family, three-family, or four-or-more family zoning. Then we got much more fine-grained as we realized that the production of housing is constrained across lots of different dimensions, not just the number of unit dimension. We eventually ended up with 100 different housing related regulatory characteristics documented in the Connecticut Zoning Atlas.

After we did the first round of the Atlas, we stood back and began to understand what the information showed collectively: that zoning is extremely different from one community to the next, that some communities allowed for lots of diverse housing types and that other communities were very homogenous.

Looking at that across the entire state gave us the insight that an understanding of zoning across more states would help us to piece together the national housing picture.

How Does The Project Scale Beyond Local?

Sara Bronin

Zoning atlases allow us to look at economic impacts of the regulatory features in the aggregate, or at a larger scale. The data allows for us to conduct that secondary analysis. For example: What what does a community lose when it constrains its housing to just one type? Does it lose small businesses. Does it lose economic diversity? Does it lose the ability to house workers across all different industries? And what are the costs of housing?

What do those costs impose on people, relative to the average incomes of households in the area? Those types of questions are enabled by this research in ways that previous research hasn't enabled because of the way this data is tied to spatial characteristics. The regulatory information is tied to geospatial data about where each zoning district lies. You can actually look to see how much of a community has non-residential areas, and where housing is located relative to transportation infrastructure, how much land is undeveloped and so on."

Will People Look Differently At Zoning's Impact?

Sara Bronin

We're examining the correlations between zoning and household income, racial and socio-economic demographics, homeownership rates and more. We tend to find that the fewer units that are allowed by a zoning ordinance, the more exclusionary the zoning ordinances, the wealthier a community is, and the less diverse community is.

We are already using the data to conduct those kinds of analyses. As more states complete their atlases, we will see more secondary research like this."

What's The Project's Big Challenge?

Sara Bronin

Right now, the biggest obstacle is the time-consuming nature of the analysis. We need to have zoning code analysts read every page of a zoning code. We need for them to upload and draw individual geospatial files. We hope to automate some of that in the future. We're looking into different ways to build up capacity in states we think are less likely to have their own teams.

Then, the momentum and the endurance factor are also there. It will take a lot for us to complete these atlases across all 50 states in a timely and coordinated manner. And so, we just have to make sure that as we continue to document the 30,000 jurisdictions with zoning across the country, that we are all pulling in the same direction and doing it as quickly and accurately as we can.

Do You Have A Personal Tie To The Project?

Sara Bronin

I grew up in Houston, the largest American city without zoning. The disjointed nature of development in Houston and the lack of beautiful and orderly environments I would say this has motivated me to think a lot about the rules of the game and how we might influence them for the better."