National Zoning Atlas

Zoning is the local law that says what may be built on a piece of land: houses or shops, how tall, on how large a lot, with how much parking. In the United States it is written by tens of thousands of cities, towns and counties, each in its own code and map.³ The National Zoning Atlas reads those codes and puts them on one national map in a common form.^1,3 It is a project of Land Use Atlas, Inc., a nonprofit.² It grew from the Connecticut Zoning Atlas of 2021, led by Sara Bronin, which found that 91 per cent of that state's land was zoned for single-family housing and 2 per cent allowed multi-family housing.²

The team has counted 33,295 jurisdictions that can zone; state law decides which ones, so Hawaii gives the power only to its counties while Minnesota has about 2,650.³ For each jurisdiction analysts find every zoning district, including overlays that sit on top of base districts and districts that exist only in the text.³ They read the code and record more than 200 characteristics per district, among them which housing types are allowed, how permits for housing are granted, minimum lot sizes, parking mandates, height caps and rules for accessory dwellings.^1,3 The maps are digitised by hand when they arrive as PDFs and cleaned when they arrive as GIS files, and protected land, water, rights-of-way and Tribal lands are cut out using national layers.³ The team does not use AI to read the codes, having concluded with the Urban Institute and Cornell Tech that it cannot yet do so accurately enough.⁴

On 24 October 2026 the live coverage figures shown on the home page were 11,848 published jurisdictions, home to about 247 million people, and about 1.45 million pages of code read.¹ By October 2026 the analysis was finished in states including Connecticut, Massachusetts, Ohio, North Carolina and Colorado, and under way in others such as Texas and California.^{7,8,9,10,11,12,13,14} Much of Texas, including Houston, has no zoning at all.¹³ Zoning changes all the time, sometimes because of the atlas's own findings, and updating a jurisdiction can take nearly as much staff time as the first build-out.⁴

Anyone can browse the map or use its Zoning Snapshots, which draw on the same data.⁴ The data itself is not open. The terms say the site's content belongs to Land Use Atlas or Land Use Labs. Nobody may download, reproduce or publish it without written permission, nor use it commercially even with permission, though screenshots of the public map may be published with credit.⁵ Downloads are licensed through Land Use Labs, set up in 2026 to pay for keeping the atlas current, which sells parcel reports, district GIS layers, 30-metre rasters, tables and a zoning API.^4,6 The citation is Bronin, Markley, Fader and Derickson, National Zoning Atlas, doi:10.4079/zoning-atlas.²

For a model of housing or growth, zoning sets the upper limit of what can legally be built on each piece of land, the starting point of the housing and land use question. Zoning is one part of the rules layer over a place.