Are you aware you can identify and improve a home’s energy efficiency by using Energy Star? If not, you’re not alone. In my experience, few—if any—contractors, utilities, municipalities or states know about the Home Performance with Energy Star program.
However, nearly everyone is familiar with the U.S. Environmental Protection Agency’s Energy Star program because it rates appliances and building materials. Energy Star also offers rating programs for new and existing commercial and residential buildings. Home Performance with Energy Star is a performance standard for existing residential buildings that provides a whole-house approach to improving energy efficiency and home comfort while helping to protect the environment. Families with Home Performance with Energy Star-certified homes are enjoying fewer drafts, consistent temperatures across rooms, better ventilation and humidity control, and lower utility bills.
Whole-house Energy Audits
We know prescriptive standards are the basis of all building codes and most utility and state and federal energy-efficiency rebates, as well as building modeling. Prescriptive standards serve as a good starting point for energy efficiency, but they do not account for the way a building actually was built and how much air leakage or thermal bridging, for example, actually are occurring. Testing a home according to the Home Performance with Energy Star protocol will help identify what really is occurring within a home.
To meet the Home Performance with Energy Star standard, an energy auditor who has special training and has been certified by the Building Performance Institute, or BPI, or Residential Energy Services Network, or RESNET, uses tools and software to perform two whole-house energy audits—one before energy-efficiency improvements are made and one after. Locate a local BPI- or RESNET-certified rater by visiting bpi.org and resnet.us, respectively. Pricing between the organizations will vary, so you will need to ask the auditor for pricing and service that meets the Home Performance with Energy Star program. Pricing will include two audits and corresponding reports, thermal imaging and models.
Although Home Performance with Energy Star requires that energy auditors be a third party to provide quality control on a jobsite, remodelers who perform energy-efficiency improvements according to Home Performance with Energy Star also must be BPI- or RESNET-certified contractors. Learn more about earning these certifications on the organizations’ Web sites.
Whole-house energy audits diagnose air movement, thermal bypass, air changes, duct leakage and combustion-zone requirements through the use of thermal imaging, pressure/depressurize testing and building modeling. After the first audit is complete, the energy auditor will provide a report of the home’s performance to the homeowner.
The report will feature thermal images, showing major and minor air leakage. It also will document performance of the home’s HVAC and water-heating equipment, lighting and appliances for an overview of the home’s total energy use.
The report also contains a Home Energy Rating System, or HERS, score. The HERS Index was established by RESNET and compares homes to the HERS Reference Home, which is based on the 2009 International Energy Conservation Code. The HERS Reference Home scores a HERS Index of 100 while a net-zero-energy home scores a HERS Index of 0. Each 1-point reduction in the HERS Index corresponds to a 1 percent reduction in energy consumption compared to the HERS Reference Home. For instance, a home with a HERS Index of 75 is 25 percent more energy efficient than the HERS Reference Home. Homes built before 2006 likely will have a HERS Index higher than 100. Not to worry because cutting the energy use of an existing home by 50 percent through a whole-building approach is achievable.