I was in Madrid in the Spring of 2010 and attended the Solar Decathalon Europe.
Its website describes the decathalon as an “international competition among universities which promotes research in the development of efficient houses. The objective of the participating teams is to design and build houses that consume as few natural resources as possible and produce minimum waste products during their life cycle. Particular emphasis is put on reducing energy consumption and on obtaining all the necessary energy from the sun.”
This is the link to there website in English: http://www.sdeurope.org/?lang=en if you wish to read more about the measures each house took to achieve the goals of the competition.
~CJ Hipp (extra credit)