The U.S. Department of Energy (DOE) now offers downloadable technical documents that tell how to achieve 50% energy savings in four commercial building sectors: general merchandise, grocery store, lodging, and medium office buildings.

The documents describe the assumptions, methods, and analyses to save 50% more energy than ASHRAE/IESNA Standard 90.1-2004.

They can be downloaded as PDFs:

General Merchandise

Grocery Store