While everyone from the Sierra Club to the National Association of Realtors believe compact, mixed-use, walkable development is an antidote to suburban sprawl, “smart growth” doesn’t just happen by itself. Indeed it can’t because most existing municipal zoning regulations make walkable urban form exceedingly difficult, if not impossible to implement. Surprisingly, this is often the case in large cities as much as it is in their sprawling suburbs. Therefore, one of the most effective ways to move smart growth from concept to reality, and at a meaningful scale, is to toss out the very zoning regulations that prevent sustainable growth from happening in the first place. Last week, Miami, Florida became the largest city in America to do so.

Downtown Miami

Earlier in the decade a phenomenal building boom quickly revealed that Miami’s existing zoning code could erode, not contribute to the city’s health and quality of life. Frustrated and concerned that such investment in the city’s urban core may not reach its full potential, Mayor Manny Diaz boldly asked city officials to throw out the city’s use-based, auto-centric zoning code and replace it with a form-based code. Building from the SmartCode, a model form-based code, Diaz sought regulations that mandated a highly walkable, transit-oriented, and sensitive urban form for the rapidly developing city. In doing so, Diaz set out to codify smart growth at an unprecedented scale.

Four years later, and with only weeks remaining in his second and final term, Mayor Diaz and smart growth advocates everywhere rejoiced as Miami’s City Commission voted 4-1 in favor of adopting Miami 21. The comprehensive zoning code re-write is now the largest application of a form-based code anywhere in the country. It includes everything from green building regulations, to requiring parking garages to have liner buildings, to re-introducing an attached townhouse building type as a means to adding density and providing better transitions between single-family neighborhoods and higher density apartment buildings. It is, in short, comprehensive.

In a country reeling from the effects of suburban sprawl and the regulations that mandate it, the adoption of Miami 21 is an historic, and perhaps watershed moment in America’s urban history. Denver, for example, will likely follow in Miami’s pattern setting footsteps by adopting its own comprehensive form-based code in a few months.

With an increasing number of precedents, it seems likely, then, that as more municipalities modernize their zoning regulations, they too may call upon form-based regulations to play a larger role in how they regulate the built environment. From city to suburb, from town to rural village, such efforts will likely work in concert with other shifting federal, state and regional policies to legalize compact and walkable development once again.

How smart.

Mike Lydon is Principal of The Street Plans Collaborative and an internationally recognized urban planner. He is the coauthor of Tactical Urbanism: Short-term Action, Long-Term Change. He works and speaks internationally on smart growth, livable cities, active transportation, and tactical urbanism. He lives in Brooklyn, NY.