A home energy rating is a useful tool that homeowners, buyers, sellers and builders can use to evaluate the energy efficiency of a planned or existing home. The information provided by an expert home energy rating can be used to compare homes on the market as well as to identify ways that a home’s energy performance can be improved. A report by a certified home energy analyst will include a HERS index, which provides a comparison of a home’s energy consumption to that of a theoretical standard home of the same size and shape.
Who Needs a Home Energy Rating?
- Builders – Developers and builders use home energy ratings to compare their new or planned construction projects with industry standards. Homes built to higher standards than surrounding properties command higher prices on the market, especially when the energy markets appear poised for rapid increases in natural gas and electricity prices.
- Home sellers – A homeowner who wants to sell can list a home for a higher price if a home energy rating that shows above average energy efficiency. The rating report can identify inexpensive steps the homeowner can take to improve the home’s energy efficiency before it goes on the market.
- Home buyers – Buyers can use home energy ratings to estimate the annual energy costs of a home they’re interested in, as well as identify major investments they may need to make as soon as a purchase is complete in order to improve energy performance. Homes with excellent energy ratings may qualify for advantageous mortgage terms with an energy efficient mortgage (EEM).
- Existing homeowners – A home energy rating can identify problem areas in an existing home so the owners can assemble an effective plan for improving their home comfort while reducing their monthly energy expenses.
What Is the HERS Index?
The Residential Energy Services Network (RESNET) is a nonprofit organization that oversees the home energy rating industry. If your home energy rating is performed by a RESNET certified energy rater, your report will include a home energy rating system (HERS) index, which is a number that compares your home energy use to a house of the same size and shape that meets specific energy performance standards included in the 2006 International Energy Conservation Code (IECC).
The HERS index shows where your house falls on a linear scale on which zero represents a home with no net energy use and 100 represents a home that meets the current IECC standards. A lower number indicates a more energy-efficient house, while a zero-energy home is one that generates as much energy as it consumes using solar panels, wind energy or other energy sources. Most American homes will score above 100 on the HERS index, with low-efficiency homes scoring 200 or more.
Factors Included in the HERS Index
The HERS index is calculated using a complex formula that takes many factors into account to assess a home’s efficiency in cooling, heating, the use of some lighting and appliances, and water heating. Some of the items that are assessed in assigning values to the variables in the formula include:
- Exterior wall construction and insulation
- Insulation of flooring above basements or other unconditioned spaces
- Ceiling, attic and roof construction, as well as ventilation and insulation
- Construction and insulation of foundations, basements and crawl spaces
- Windows and doors, including types of glazing and framing, and quality of weatherstripping
- Ductwork design and airtightness
- HVAC equipment types and efficiencies
- Water heater fuel and energy efficiency
- Energy efficiencies of some major appliances and lighting
Once you have your energy rating report in hand, you can use it to compare your home’s energy use with a theoretical standard home the same size and shape as yours. The report will help you prioritize home energy upgrades to get the best returns from your investments in the form of increased home comfort and lower energy bills.
Learn more about getting a home energy rating for your Baltimore home, as well as Griffith Energy Services, Inc.’s energy services, or give us a call at 888-474-3391.
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