air sealing Air Sealing
Combined with proper insulation, air sealing plugs holes or cracks that let air into your home. These leaks are common around doors, windows and attics. Sealing can be accomplished with caulk or weatherstripping.
blower door Blower Door Test
A blower door test is used locate areas where air leaks occur within home. This powerful fan mounts into the frame of an exterior door. Once energy improvements are done, a blower door is used to ensure air sealing work was done properly.
After briefly running a combustion appliance, a Home Performance Contractor can measure how much gas leaks into a home – these leaks can be dangerous and should be properly vented through a chimney or flue.
BPI logo BPI Certification
The Building Performance Institute is a national organization that trains and accredits Home Performance Contractors that meet their standards and quality assurance protocols.
  Building Envelope
The outer shell of a building that separates the outside air from the inside air. The envelope usually goes from the attic floor to the basement.
CFL bulb CFLs (compact fluorescent lightbulbs)
A single 20-watt CFL provides the same amount of light as a 75-watt incandescent light bulb and lasts up to seven times longer.
  Ducts (or ductwork)
A series of tubes that circulate air from a furnace or air condition system. These tubes move air from rooms back to the main system. For example, when you turn the thermostat higher, the furnace heats the air and sends it out through ducts into rooms and simultaneously pushes cold air out of the rooms back to the furnace.
Efficiency First
energy audit Energy Audit
An evaluation of a home to see where energy is being lost and how efficiently current heating and cooling systems as well as appliances are operating.
A program sponsored by the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Energy (DOE) to help consumers make informed decisions about energy efficiency products and energy usage in all types of buildings including homes.
Forced Air Heating or Cooling 
The most common way to heat or cool a home. The air can be filtered and then distributed (forced) through ductwork into your home’s rooms through registers.
Greenhouse Gases (GHG)
Atmospheric gases, primarily carbon dioxide, methane, and nitrous oxide, that heat the Earth’s atmosphere.


HERS index HERS Index
Home Energy Rating System. A rating system developed by the ResidentalEnergy Services Network (RESNET) that scores homes on a scale of 0 to 100. The lower a home’s score, the more efficient it is.
Home Energy Yardstick
An online tool provided by ENERGY STAR that allows homeowners to enter their current energy usage information and compare their home to other homes.

Sometimes called “Cash for Caulkers,” this proposed legislation aims to give rebates to homeowners for installing energy efficiency appliances, adding insulation, or other whole-home energy improvements.
Quality Assurance (QA)
A process to ensure Home Performance energy improvements have been done properly and meet safety standards.

Used to measure how well a material resists heat flow. A high R-value means the insulation is keeping heat in your home in cold seasons, and heat out in warm seasons.

SEER, Seasonal Energy Efficiency Ratio
A measure for energy efficiency of an air conditioning system. A high SEER rating means the cooling system will be efficient over an entire season.

Weatherization or Weatherization Assistance Program (WAP)
A government program that does energy improvements on homes for families with lower incomes.