A Home Energy Rating is a measurement of a home’s energy efficiency, used primarily in the United States. Home energy ratings can be used for either existing homes or new homes. A home energy rating of an existing home allows a homeowner to receive a report listing options for upgrading a home’s energy efficiency. The homeowners may then use the report to determine the most effective ways in which to upgrade the home’s energy efficiency. A home energy rating of a new home allows buyers to compare the energy efficiency of homes they are considering buying.
Contents |
A home energy rating can be used to gauge the current energy efficiency of a home or estimate the efficiency of a home that is being constructed or improved. A home energy rating of a home prior to construction or improvement is called a “projected rating.” A home energy rating that is used to determine a home’s current efficiency is referred to as a “confirmed rating.”
Energy assessments take into account different climatic conditions in different parts of the country and are benchmarked according to average household energy consumption particular to a given climatic region.
Ratings provide a relative energy use index called the HERS Index – a HERS Index of 100 represents the energy use of the “American Standard Building” and an Index of 0 (zero) indicates that the building uses no net purchased energy (a Zero Energy Building). The lower the value, the better.
For capitalizing a building’s energy performance in the mortgage loan, certification of “White Tags” for private financial investors, and by the US government for verification of building energy performance for such programs as federal tax incentives, the United States Environmental Protection Agency’s Energy Star program and the U.S. Department of Energy’s Building America Program.
The HERS Index was introduced in 2006 and replaced the earlier "HERS Score", which ran in the opposite direction: The higher the value, the better.[1] In 2009, the U.S. Department of Energy presented a new scale, the "EnergySmart Home Scale (E-Scale)", "based on" the HERS Index, apparently simply by subtracting the HERS Index from 100. In this new scale, higher values correspond again to better performance.[2]
Projected ratings give home owners and builders an estimate of what a home’s efficiency will be like after construction or improvements, so that they may determine the most cost-effective route to improve a building’s efficiency. A confirmed rating, which indicates the home’s current efficiency, requires an inspection of the home from an energy rater. The home energy rater reviews the home to identify its energy characteristics, such as insulation levels, window efficiency, wall-to-window ratios, the heating and cooling system efficiency, the solar orientation of the home, and the water heating system. Performance testing, such as a blower door test for air leakage and duct leakage, is usually part of the rating.
To provide Home Energy Ratings, individuals must attend a HERS Rater training program and pass the national rater test. The industry standard for HERS training is a 40 hour course that spans between 5 and 10 days although some trainers offer self paced online programs. Students learn the basics of building science, proper use of duct blaster and blower door equipment, RESNET standards, and mortgage and white tag related information.
There are no prerequisites for individuals who wish to obtain HERS Training and take the national rater test. However, HERS subject matter is difficult and the learning curve may be quicker for individuals who have a background in the construction or home inspection industry. The test is open book and open note but students may not use web resources to answer questions.