How the Battle for Sunlight Shaped New York City

Ever since 19 century city commissioners laid a grid on the hilly island of Manhattan, New York City has been squeezing skyward. That’s meant natural light has always been in short supply—for some New Yorkers more than others. Access to sunshine was one of the main drivers of the first zoning laws, as a new exhibit at the Museum of the City of New York, Mastering the Metropolis, explores. Here are five key points along New York City’s never-ending quest to stay lit, the natural way.

Finding ways to bring natural light into interior spaces has long been a crucial consideration for architects, but regulating sunlight wasn’t such a pressing question until the middle of the 19 century, when urban populations spiked. Low-wage industrial workers were often packed into damp, crowded, often windowless tenements, usually located near factories. Progressive reformers pressed city and state lawmakers to crack down on such dwellings, and in 1867, New York State passed its first Tenement House Act, requiring (among other things) that every habitable room needed a window—a law that still exists in the city’s building codes today. Subsequent laws specified what types of spaces windows had to open towards (first, dim shafts; later, brighter courtyards). Soon, other cities followed.