How Energy Codes Make Homes More Efficient

HOW ENERGY CODES MAKE HOMES MORE EFFICIENT Household energy use is lower than it was in the '80s, even as we buy up PlayStations and iPhones. Why? Thank stronger energy codes. Building energy codes set minimum legal standards for the energy efficiency of new homes. That's good for the environment because it lowers carbon emissions, and also good for Americans' bank accounts. Houses built to stronger codes are up to 44% more efficient and can save a family hundreds of dollars a year on energy costs. The two hypothetical properties depicted below-a 1983 house and a 2012 house-show the evolution of an average home and a side-by-side comparison of how energy codes make a surprising difference in home energy efficiency. 1983 HOUSE [MEC) 2012 HOUSE (IECC) MODEL INTERNΑΤIONAL ENERGY ENERGY CONSERVATION CODE CODE DUCTS DUCTS Insulation: R-5 Isulation: R-8 Air leakage testing: Not required Air leakage testing: Mandatory INSULATION An R-value indicates thermal resistance. The higher the R-value, the more effective the insulation. R-13- Walls R-20 R-19 R-6 Ceiling Floor R-38 R-19 ENVELOPE ENVELOPE Air leakage testing: Not required Air leakage testing: Mandatory WINDOWS RAD A U-value measures the rate of heat loss through a material. The lower the U-value, the more effective the heat retention. LIGHTING 75% of lamps must be high efficiency LIGHTING No requirement U-value: 1.1 U-value: .35 Solar Heat SHGC: .25 Gain Coefficient: No requirement DOORS U-value: .6 U-value: .35 ENERGY STA THERMOSTAT ВОTH HOUSES Programmable THERMOSTAT Location: Atlanta, Georgia Adjustable 2,500 square feet 28-foot frontage, two stories with 8' ceilings and 1' between stories, basement with furnace, attic with ducts. IMT estimates that the residents of the 2012 house will pay almost $400 less in energy costs (in 2012 dollars) than the residents of the 1983 house, thanks to stronger energy codes and appliance standards. Over the past three decades, the share of electricity used by appliances and electronics in U.S. homes has nearly doubled, from 17 percent to 31 percent. However, energy use per household fell 31 percent*. As the U.S. population and use of personal electronics rises, codes will need to stay stringent to keep energy use in check. IMT Institute for Market Transformation Global Buildings Performance Network Source: Residential Energy Consumption Survey, U.S. Energy Information Agency. *http://consumption/residential/reports/electronics.cfm