Jerry Adler in Smithsonian:
Twenty feet under Delancey Street in Manhattan is a trolley terminal that hasn’t been used in 65 years—a ghostly space of cobblestones, abandoned tracks and columns supporting vaulted ceilings. An ideal place for the city to store, say, old filing cabinets. Yet when the architect James Ramsey saw it, he imagined a park with paths, benches and trees. A park that could be used in any weather, because it gets no rain. That it also gets no sunlight is a handicap, but not one he couldn’t overcome. If the 20th century belonged to the skyscraper, argues Daniel Barasch, who is working with Ramsey to build New York’s—and possibly the world’s—first underground park, then the frontier of architecture in the 21st is in the basement.
There are advantages to underground construction, not all of them obvious, says Eduardo de Mulder, a Dutch geologist. 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. Underground real estate in crowded Shanghai and Beijing, expanding at around 10 percent a year since the turn of the century, is projected to reach 34 square miles in the capital by 2020. Helsinki’s master plan calls for significantly expanding its tunnels and more than 400 underground facilities, which includes a seawater-cooled data center.
Of course, you give something up to relocate underground, namely, windows. Even de Mulder thinks below-ground living (as distinct from working and shopping) has a large obstacle to overcome in human psychology.