As the recession grinds on, some consultants are finding an emerging outlet by updating older buildings from power hogs into green stewards. The trend is attracting a fresh round of eco-savvy tenants. Chicago is home to two large projects, examples of advancing efforts to green up existing buildings. In early December, 172 buildings nationwide were certified under the U.S. Green Building Council’s LEED for Existing Buildings Rating System, a program created in 2004. More than 2,000 other buildings are seeking to obtain such certification, according to the Washington, D.C.-based group. Photo: Merchandise Mart Properties Inc. The 79-year-old Mart’s green makeover
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.