The U.S. Green Building Council and the Green Building Certification Institute have released an improved version of the green-building rating system, which standardizes language across all categories and overhauls the LEED-accredited professional system, turning it into a tiered program. The current release includes LEED 2009, LEED Online Version 3 and a new certification process based on ISO standards. It also updates all the LEED categories at once, including those for new construction, schools, core and shell, commercial interiors and existing buildings. LEED Online V3, the implementation tool, has been retooled to be faster, more responsive and stable. USGBC has seen
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.