LEED: Abbreviation for Leadership in Energy and Environmental Design, a four-level rating system established by the U.S. Green Building Council  (GHE is a proud member).  

Buildings are rated in each of five categories: sustainable sites, water efficiency, energy and atmosphere, materials and resourcse, and indoor environmental quality.

Here is some info on two LEED-certified buildings with which I'm very familiar.  They were developed by a non-profit organization in Chicago, Mercy Housing Lakefront.  Working there was how I got my first taste of green building.  Their first LEED building was Wentworth Commons, a 4-story, 65,800 sq. ft. apartment building with 51 units and supportive services for people who were formerly homeless.

Mercy Housing Lakefront's second green property, which has received multiple accolades and international attention, is the Margot and Harold Schiff Residences.