The US Green Building Council (USGBC) has approved new guidelines for Leadership in Energy and Environmental Design (LEED) for commercial, which will be introduced in 2009.
The green-building rating system has undergone a re-weighting of credits, changing allocation of points to reflect climate change and energy efficiency as urgent priorities. LEED has been criticized for allocating relatively few points to energy efficiency and renewable energy.
Carbon Solutions Group believes that REC purchases used for LEED projects should be based on the concept of vintages. The importance of vintage based purchases is supported by World Resources Institute as stated previously, and by Green-e Energy as follows: