There aren't many places in midtown Manhattan to carve out a new 2.5-acre (1-hectare) park, but the U.S. Postal Service found a spot seven stories above street level—on top of the sprawling building where 12 million pieces of mail are sorted for New Yorkers each day.
Last year, the largest green roof in New York City opened atop the Morgan mail processing facility at Ninth Avenue and 30th Street.
(Related, from National Geographic Magazine, "Up on the Roof")
The park—complete with benches, an art wall, and drought-tolerant native perennials—helps to cool the workspace for the 1,800 people who handle virtually the bulk of letters and packages delivered in Manhattan and the Bronx.
Air conditioning can be a major cost in a city facility with such a large workforce. So when it was time to replace the building’s black asphalt roof in 2007, the Postal Service began exploring ways to reduce the surface temperature. It turned out that the facility could support the weight of soil and vegetation, and would benefit in numerous ways from a park-like installation.
(Related, from National Geographic Magazine, Green Roof Photos)
The green roof is designed to last 50 years, twice as long as the roof it replaced. And the vegetation—including drought-tolerant ground covers like coral carpet, Immergrunchen, and John Creech—will suck down storm water. That will reduce runoff into the New York municipal water system by as much as 75 percent in the summer and 40 percent in winter, the Postal Service says. The Postal Service also was able to recycle and reuse 90 percent of the old roof in the new project.
Originally, the Postal Service estimated that the $4 million green roof project would help save $30,000 in annual energy expenses, but recently officials said energy costs at the Morgan facility actually have been slashed in half, a savings of $1 million per year. That’s due not only to the roof, but to a suite of other improvements to reduce the 1933 building’s energy leakage, including the replacement of 1,600 old windows.
The Morgan facility was named for Edwin Morgan, who rose from New York letter carrier to serve as postmaster general of the city under President Theodore Roosevelt. The landmark building has a new place in history, as the first Postal Service green roof (See USPS green roof time lapse video) and forerunner to a number of projects around the country aimed at slashing energy use for U.S. mail handling and delivery by more than 30 percent by 2015.
The Postal Office has a two-year monitoring program set up at the Morgan facility, not only to test its impact on the building, but on the surrounding neighborhood on the edge of Chelsea. "We are hoping to reduce Manhattan's 'heat island' effect," says Sam Pulcrano, vice president of sustainability for the Postal Service.
(Related: "Get Cool, Paint Your Roof White")