HERS® score/index, home energy rating system (HERS) created in 1995 by third party non profit residential energy services network (Resnet).  The HERS score  is nationally recognized by the federal government, environmental protection agency (EPA) and the mortgage industry. The Hers score is a numeric numeral that directly translates into the energy efficiency of the selected inspected home. The trained and certified ecorater inspects the home and benchmarks the home against a reference home. A computer model of a home that is the same shape and size.

The individual numerical HERS score is then applied  towards the HERS index with numbers ranging from zero to 150. The lower the HERS score the more energy efficient the home is constructed. A net zero home is located at the extreme end of the Hers scale. The net zero home produces as much energy as it consumes. As green building science evolves and becomes more efficient some homes are now producing a negative HERS score(-3). Producing more energy than the home can consume pushing energy back into the electrical grid. Research is now being conducted to install energy storage components within these structures.   In the near future energy and water efficiency will be included in the green mortgage underwriting. As these two products directly effect the annual cost of owning and maintaining a home.

A standard new home would have a numeral rating of 100. A home with a HERS rating of 70 is 30% more energy efficient than a standard new home. A home with a numerical rating of 130 is 30% less energy efficient than a standard new home. The Hers rating is one of the green underwriting tools  that is used in certified green building designations to use recognized legitimate green building science in sustainable homes to qualify for a recognized green certification. The HERS score is one of the green “tools”  to eleminate “greenwashing!”