Dive summary:

• A substantial portion of home-buyers want houses that will save them money on energy bills, according to the latest figures from the U.S. Energy Information Administration.
• In 2011, the nation averaged 26% of homes meeting the voluntary standards in the 2006 Environmental Protection Agency-initiated Energy Star specifications.
• The EPA released a new Energy Star version this year, and it raises the bar, requiring that homes use 15% less energy than would be required by the 2009 International Energy Conservation Code. The EPA has two ways that houses can quality – meeting predefined standards or energy modeling.

From the article:

Homes built to voluntary ENERGY STAR® specifications made up about 26% of all new homes constructed in the United States during 2011. ...