Learn the Lingo


Glossary of Terms for the Home Performance Industry

Building Performance Institute (BPI) – A leading developer of technical standards for Home Performance and weatherization retrofit work that are recognized across North America. From these standards, BPI has developed training programs, professional credentialing for individuals, company accreditations and quality assurance programs for the industry. For more BPI terminology, see the BPI Terms and Definitions sidebar to the right of this page.

Bundled Efficiency Program – An existing home program that targets consumers in existing homes by offering education and/or incentives on multiple end uses and/or systems in the home. A bundled efficiency program packages together program offerings into one touch-point with the customer and does not include a comprehensive assessment of a home’s energy usage.

Conversion Rate – rate at which property owners follow through with retrofit measures recommended as a result of a home performance evaluation or energy audit.

EPA Water Sense Specifications – WaterSense, a partnership program sponsored by EPA, seeks to protect the future of our nation's water supply by promoting water efficiency and enhancing the market for water-efficient products, programs, and practices. WaterSense will help consumers identify water-efficient products and programs.

Existing Homes – Single-family and small multifamily (four units or less) housing units.

Existing Homes Programs – Energy efficiency programs that have a goal of reducing energy usage in existing homes.

Home Energy Audit – an assessment of how much energy a home consumes and a set of recommendations for ways to decrease the home’s energy usage. Audits take a variety of forms, from the simplest do-it-yourself version to the more comprehensive versions conducted by a BPI-certified building analyst or HERS rater. An audit will pinpoint where your house is losing energy and show you how to correct the problems to save money, improve comfort, improve indoor air quality, and conserve hot water and electricity. www.energysavers.gov/your_home/energy_audits/index.cfm/mytopic=11160

Home Energy Rating Services (HERS) Index – a scoring system established by the Residential Energy Services Network (RESNET) in which a home built to the specifications of the HERS Reference Home (based on the 2006 International Energy Conservation Code) scores a HERS Index of 100, while a net zero energy home scores a HERS Index of 0. The lower a home’s HERS Index, the more energy efficient it is in comparison to the HERS Reference Home. A home energy rating involves an analysis of a home’s construction plans and onsite inspections. Based on the home’s plans, the Home Energy Rater uses an energy efficiency software package to perform an energy analysis of the home’s design. This analysis yields a projected, pre-construction HERS Index. Upon completion of the plan review, the rater will work with the builder to identify the energy efficiency improvements needed to ensure the house will meet ENERGY STAR performance guidelines. The rater then conducts onsite inspections, typically including a blower door test (to test the leakiness of the house) and a duct test (to test the leakiness of the ducts). Results of these tests, along with inputs derived from the plan review, are used to generate the HERS Index score for the home. www.energystar.gov/index.cfm?c=bldrs_lenders_raters.ng_HERS

HERS Rater – An energy analyst who is trained to compile data about a home, its building envelope and energy features, and then determine a predicted energy performance using the Home Energy Rating System (HERS). In addition to visual inspection, the rater will use testing equipment, such as blower doors and duct testers, to determine a “HERS Index” (see above) for the home. To qualify as a certified rater, the analyst must meet the requirements of RESNET(see explanation below). www.energystar.gov/index.cfm?c=bldrs_lenders_raters.nh_HERS

HERS II Rater (California Only) – An energy analyst who is trained to compile data about existing and newly constructed residential buildings that include single-family homes and multi-family buildings of three stories or less. The new HERS regulations establish a systematic process for the delivery of whole-house home energy ratings that provide California homeowners and home buyers with information about the energy efficiency of the homes they live in or homes they are considering for purchase. The ratings also provide evaluation of the cost-effectiveness of options to achieve greater energy efficiency in those homes. www.energy.ca.gov/HERS/index.html

Home Performance – A comprehensive whole-house approach to identifying and fixing comfort and energy efficiency problems in a home. A drafty house, rooms that are too hot or too cold, and high energy bills are all common issues for homeowners. A quality installation of a new heating or air conditioning system, buying replacement windows, or adding more insulation may fix part of the problem, but home performance looks at the entire package, including energy efficiency, comfort, durability, cost and health and safety.

Home Performance Contractor – Companies or sole proprietors engaged in Home Performance retrofitting in accordance with EPA guidelines, including before and after testing procedures, combustion safety testing, and a house-as-a-system approach incorporating multiple remediation measures. Contractors may be general contractors who oversee subcontractors, or businesses that run internal crews to conduct retrofitting projects on homes. Contractors may be licensed and insured as required by their state or jurisdiction of operation.

Home Performance with ENERGY STAR (HPw/ES) – A national program from the U.S. EPA and U.S. DOE that offers a comprehensive, whole-house approach to improving energy efficiency and comfort at home, while helping to protect the environment. HPwES programs are currently offered in 29 states. Under this program model, each home is assessed comprehensively by properly trained and certified contractors and/or consultants. Home Performance with ENERGY STAR takes a whole home approach to achieve not only energy efficiency, but also health, safety, and comfort. www.energystar.gov/index.cfm?c=home_improvement.hm_improvement_hpwes

Non-Energy Benefits (NEBs) – The additional benefits created when a homeowner completes home performance upgrades. These include: cost savings, improved comfort and health, industry development, job creation, and reductions in GHG emissions.

On Bill Financing (OBF) – A utility based method of providing low or zero cost financing for residential energy efficiency improvements. The homeowner or tenant repays the loan through their monthly electricity bill by paying an additional monthly fee.

Prescriptive Measures – Programs that focus on providing incentives for the purchase and proper installation of specific energy saving equipment, such as furnaces and water heaters, super-high-performance major appliances such as refrigerators and washing machines, or changes to a building’s envelope such as insulation and duct sealing.

Property Assessed Clean Energy (PACE) – Financing mechanism that enables local governments to finance renewable energy and energy efficiency projects on private property, including residential, commercial and industrial properties. The programs eliminate the chief barrier to clean energy installations-- the large upfront cost-- by offering the property owner a loan that can be repaid in fixed payments as part of their property tax bill. Generally, PACE is rooted in traditional land-secured municipal finance. A local government creates an improvement district; a bond, secured by real property within the district, is issued; and the bond proceeds are used to fund renewable energy and energy efficiency projects.

Residential Energy Services Network (RESNET) – a membership 501(c)(3) nonprofit organization that set the standards of quality for the building energy performance industry, including standards for building performance software, HERS raters’ knowledge base & skill sets, and quality assurance evaluations. RESNET's standards are officially recognized by the U.S. mortgage industry for capitalizing a building's energy performance in the mortgage loan, certification of "White Tags" for private financial investors, and by the federal government for verification of building energy performance for such programs as federal tax incentives, the Environmental Protection Agency's ENERGY STAR program and the U.S. Department of Energy's Building America Program. www.natresnet.org

Whole Home Program – A program that incorporates building science principles to comprehensively assess existing conditions of a home’s energy usage, as well as how all the systems within the home interact. This assessment is then used to create a detailed work scope, or plan, to achieve the greatest energy savings for the home over a long period of time. A whole home program relies on properly trained and certified technicians to complete the installation of measures incorporating best practices to nationally recognized standards, typically followed up with third-party quality assurance inspections. www.cee1.org