Deep beneath the streets of New York City's Lower East Side, a new type of green space is coaxed out of the darkness. Delancey Underground, a 1.5-acre space that formerly served as a trolley terminal, has gone unused since 1948. To designer James Ramsey, this abandoned cavern seemed like the perfect place to build a public park called the LowLine, powered by a remote skylight system of his own invention.
Despite the challenges of natural light, there are a few key advantages spurring architects to head for the basement, according to Smithsonian magazine:
Although excavation is expensive and technically challenging in places like the Netherlands with a high water table, underground space is cheaper to maintain—there are no windows to wash, no roof or facade exposed to weather. The energy cost of lighting is more than offset by savings on heating and cooling in the relatively constant below-ground temperature. Cities with harsh winters or blazing summers have been at the forefront of the building-down trend.
Ramsey is not the only one who sees opportunity in digging down rather than building up. Mexico's BNKR Arquitectura released plans a few years ago for The Earthscraper, a 65-story inverted pyramid filled with housing, shopping and offices designed to extend beneath the main square of Mexico City. Not only are these underground structures energy efficient, but they give architects the freedom to build in historical areas—like the center of Mexico City, or Bolzano, Italy, where a new subterranean school stretches threes stories down—without disturbing the architectural context of the city above.
There are other benefits. Not to get too morbid here, but as author Annalee Newitz points out in her excellent book Scatter, Adapt, and Remember: How Humans Will Survive a Mass Extinction, underground cities may be humanity's last hope if the surface of the Earth becomes unlivable, like during a nuclear apocalypse. "As more cities send vital roots underground, we create a world that is inadvertently preparing itself for a radiation emergency," she writes. "The more we make the subsurface livable, the more likely it is that humans will survive to see the next several millennia."
Whether people are ready yet to live, work and play far below the surface is another issue. The Earthscraper has yet to be built, and construction on the LowLine isn't set to begin until 2017, though the project was popular enough to raise more than $155,000 on Kickstarter.
Read more at the Smithsonian magazine.