HERS stands for Home Energy Rating System. Most all builders are pledging to get all their homes HERS rated. A HERS score of 100 is a home built to the minimum 2006 IEEC building code. A HERS score of 0 is a net zero energy home.
You can get to a score of around 60 through efficiency improvements such as lower U-value windows, higher insulation, higher efficiency HVAC and hot water systems, orientation, higher efficiency lighting and appliances. To get to zero you will need to add a renewable power system such as solar, wind turbine, or micro-hydro turbine.
Joe Bowling is president and founder of Energy Wise Solutions, a renewable energy/energy efficiency company based in Charlotte, N.C. The company provides services for homeowners and businesses including home energy audits, solar consulting, solar equipment sales, NABCEP certified installations, solar repairs and solar thermal, and green building verification for LEED, Energy Star and NAHB Green Building.