The architects of 2012 Architecten in Rotterdam, The Netherlands, use discarded materials for their design purposes. But in order to work with waste, one needs certain tools. One of these is the "harvest map," a guide to regional dump sites and the materials they contain. Another tool is the Superuse Web site, where architects and the general public share designs that incorporate waste materials.

"e²: the economies of being environmentally conscious" is an ongoing PBS documentary series about solutions to the world's most pervasive environmental challenges. The series continues its flagship coverage of sustainable architecture with "e² design season three," featuring innovations in green building and planning from around the globe. Check your local PBS listings for television broadcast dates in your area.

The "e²" series and its video podcasts are produced by kontentreal, and distributed within the United States by PBS. More information is available at pbs.org/e2/ and e2-series.com/