Interested parties have until Jan. 14 to take advantage of the first of two public comment periods on the draft update of the popular Leadership in Energy and Environmental Design (LEED) green-building rating system. The U.S. Green Building Council hopes to release the revised system in November 2012, after an August 2012 ballot. The proposed system builds on LEED 2009, which includes the alignment and weighting of credits for certification, says USGBC. The upcoming version also develops the LEED 2009 framework that allows credits to be applied to specific building types. The draft increases emphasis on integrated process and building
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.