Home Energy Ratings: A Primer

Getting information on the relative energy efficiency of washers, dryers, heating systems, computers and cars is easy for a consumer - just check the product efficiency label on the product. Ironically, when buying a home, the largest single purchase and by far the biggest source of energy bills for most families, consumers do not have such a reference. A home energy rating, comparable to checking the miles per gallon sticker on a new car, fills that need.

The home energy rating is a standard measurement of a home’s energy efficiency. An energy rating allows a home buyer to easily compare the energy costs for the homes being considered. A home owner who wants to upgrade the home’s energy efficiency can use the energy rating to evaluate and pinpoint specific, cost-effective improvements.

Home energy ratings involve an on-site inspection of a home by a residential energy efficiency professional, a home energy rater. Home energy raters are trained and certified by the operating home energy rating system. As a rule, home energy raters come from either the housing or energy fields. Their backgrounds include experience as home inspectors, appraisers, energy auditors, low-income weatherization contractors, and energy efficient home builders and designers.

The home energy rater inspects the home and measures 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. Diagnostic testing, such as blower door for air leakage and duct leakage testing, is often part of the rating.

The data gathered by the home energy rater is input into a computer program and translated into points. The home receives a point score between 1 to 100, depending on its relative efficiency. An estimate of the home’s energy costs is also provided. The home’s energy rating is then equated to a Star rating ranging from a 1 Star for a very inefficient home to a 5 Star for a highly efficient home. Along with the rating sheet, a home owner receives a report listing cost-effective options for improving the home’s energy rating.

One of the major differences between a home energy rating and a energy audit or weatherization assessment is that the rating is a recognized tool in the mortgage process. Home energy ratings are valuable to the housing industry and can be utilized in a variety of ways.