On a cold morning in 1912, the Equitable Building at 120 Broadway in New York City caught fire from a carelessly thrown match into a trash can.  Firefighters tried to save the building but -20^oF temperatures turned the water from their firehoses into frosty icicles. The structure was lost.  The Equitable Building had been constructed in 1870 on a roughly one-acre block bounded by four streets. It was one of New York’s first skyscrapers, coming in at a whopping eight stories.  However, by 1912, the newer buildings surrounding it were over twice as tall. When the rubble was removed and the site cleared, something unexpected happened.

Workers in the lower floors of the surrounding buildings experienced sunlight shining into their windows for the first time ever. The air seemed cleaner. People were happier and felt healthier. They were so overjoyed with their changed urban environment that they petitioned City Hall to purchase the land and build a city park. Instead of selling, the property owner constructed a massive 36-story office building that dwarfed its neighbors, housed 15,000 workers, and ominously covered every inch of the site.   It was the largest building in the world. It cast a shadow roughly six times the size of its footprint, completely engulfing adjacent buildings in even more darkness.

At that time, real estate developers enjoyed unfettered private property rights supported by decades of court precedent. The property owner had full control, and technological innovations were allowing buildings to be taller and bulkier.  The sky really was the limit. But even though you could build anything you wanted, so could your neighbor. Because of the uproar over the new Equitable Building, people began to realize that the unconstrained power of the individual property owner was creating too much uncertainty and volatility in the real estate market and was hurting the collective health of the community.

A lawyer, subway planner, and activist named Edward Bassett had an idea. He theorized that the only government power that the courts might consider superior to private property rights was the police power to protect public health and safety.  He did experiments and prepared studies that scientifically documented how sunlight and clean air could not reach the street level around these massive skyscrapers.  He proposed government-regulated building height limits and building setbacks whereby the first few floors of a building could cover the entire site, but as the building got taller, successive floors had to be set back to lessen the bulk of the building as it rose to the sky. He divided the city into zones, each with different height limits and setbacks. After much politicking and coalition building, his codes were adopted in 1916. Some architects designed literally to the code’s limits, creating skyscrapers that looked like awkward stair steps. Others turned the limitations into inspiration, designing masterpieces like the Empire State Building and the Chrysler Building.

Cities around the country adopted their own zoning ordinances. Having been denied a permit to construct industrial buildings in a residential zone by the Village of Euclid, Ohio, the Ambler Realty Company sued, taking their challenge all the way to the Supreme Court.  In 1920, the Supreme Court ruled six to three in favor of Euclid, confirming that zoning ordinances were Constitutional. The Court’s majority relied on Bassett’s argument that zoning limitations are a legitimate use of a city’s police power to protect the public health and safety of a community.

The court case is Euclid v. Ambler. A code that establishes zones with allowed uses, height limits, and building setbacks is now known as a Euclidean zoning code. And the (new) Equitable Building is now 105 years old and designated a National Historic Landmark. One of its many tenants is the New York City Department of City Planning.