Zoning and Transparency

Zoning impacts the most physical elements of our communities and daily lives — from the location of your local supermarket (and what you can purchase there) to the size and height of your home. When it comes to being transparent about the zoning process and its outcomes, many local governments do release public information and post it online, but the format, quality, completeness, and scope of this information varies widely. Despite this, there are still common trends and norms to municipal zoning that we can assess to reveal the landscape of this regulatory process and related data and to see where there might be room for improvement.

Sunlight Research and Blogs on Zoning Data

Zoning Data Research — This editable research document explores which cities release zoning data, who uses the data, and more.

The Landscape of Municipal Zoning Data — Cities have many different levels of disclosure when it comes to releasing zoning data online: find out what kinds of information cities are sharing.

Zoning Data Recommendations

Recommendations for Stronger Zoning Data — While zoning is an especially complex dataset because of its its many variables from city to city, among other reasons, there are a few steps cities could take to improve the quality of this data and its ability to be reused and analyzed. Many of these ideas can be found in our Open Data Policy Guidelines.

  1. Mandate timeliness — Releasing zoning data in a timely manner, and updating it when changes are made, gives people a chance to be aware of and react to changes that might impact them.

  2. Use open formats — Open, structured data helps encourage reuse and analysis, and for zoning data releasing several different kinds of open structured data might be helpful for different levels of users. CSV or XML files are formats that can be used for spreadsheets with zoning information. File formats specific to geospatial software, from shapefiles to GeoJSON, can help encourage the development of more advanced apps and mapping of zoning data.

  3. Include metadata — Including metadata in zoning data releases can help ensure data quality and make archiving and organizing easier, especially as the amount of data increases.

  4. Publish historical data — Governments should consider publishing versions of zoning data so people can track how the regulations have changed over time. These versioned datasets could help reveal patterns in how zoning regulations change throughout a city’s history.

  5. Publish information about both the zoning process and its outcomes — As we noted in our look at the landscape of municipal zoning data, it is important to include information about both the zoning process and its effects. Without this information about zoning regulations and how those regulations are created, people are left with an incomplete picture of how they can interact with zoning.

The Impact of Opening Up Zoning Data

From empowering apps that contextualize the information to investigative news stories exploring who tries to influence zoning regulations, open zoning data can have a big impact on a community. Learn more below and on our blog.


  • Second City Zoning — This app lets users visually explore how zoning regulations play out across the city of Chicago.

  • Zoner — This mobile app lets users calculate how much floor area they could build on certain properties in New York City based on zoning codes

  • Zonability — This app uses zoning data and other information to create a profile of what could be done on properties in Austin or Round Rock, Texas.

News stories: