Which means there are more than 30,000 different sets of zoning rules in America. AdvertisementFor the first time, a team of researchers is compiling every city's zoning rules into a National Zoning Atlas. Cities and towns in both states, they could see, penalize or outright prohibit duplexes and other forms of housing that bring down prices and help prevent urban sprawl. Enacting a more permissive set of zoning rules gave everyone something they wanted. "The state of California has been passing zoning change after zoning change," Freemark says, "but it's still facing low housing construction statewide."

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Persons: you've, nix, we'll, Sara Bronin, It's, Bronin, we'd, Kendall Cotton, Lefty, Cotton, Montana, Yonah Freemark, Freemark, Italo, Marco Polo, Kublai Khan, Polo Organizations: America, Zoning, Cornell University, Big Sky, California ., Urban Institute Locations: America, we're, Milford , Connecticut, Montana, California, California . Cities, Los Angeles, Missoula, LA