When designing and building a new home, attention to energy-efficiency details matter. Good decisions will reduce fuel use and greenhouse gas emissions, adding up to decreased utility bills and increased comfort.
More than 1 million homes in the United States have been built to Energy Star standards since the program began labeling homes in 1995.
Families living in Energy Star-qualified homes will save more than $270 million this year on their utility bills, while avoiding greenhouse gas emissions equivalent to those from 370,000 vehicles.
Typical energy savings are $200 to $400 a year per home.
To earn the Energy Star label, a home must meet U.S. Environmental Protection Agency guidelines certifying it as at least 15 percent more energy efficient than homes built to the 2004 International Residential Code. Typically, they are 20 percent to 30 percent more efficient than homes built to standard codes.
Energy-saving opportunities continue to grow.
A “dream home” in Boise, Idaho, raffled off as a fundraiser for St. Jude’s Children’s Research Hospital was built as a “net zero” home. That means it produces as much energy as it consumes during a year.
Every component was selected to ensure the home uses as little energy as possible. It is connected to the grid, both to draw power and share surplus generation.
While styles vary, most energy-efficient homes have some common basic elements: a well-constructed and tightly sealed thermal envelope; controlled ventilation; properly sized and installed heating and cooling systems; and energy-efficient appliances.
The walls, roof, insulation, air and vapor retarders, windows, weatherstripping and caulking combine to shield the living space from the outdoors.
An energy-efficient house has much higher insulation R-values than required by local building codes. R-value is the ability of a material to resist the transfer of heat.
Properly installed insulation in floors, walls and the attic ensures even temperatures throughout the house, reduced energy use and increased comfort. Gaps and compaction of insulation reduce its effectiveness.
Using caulk, weatherstripping, foam and gaskets to seal holes and cracks in the home’s envelope and heating and cooling duct systems helps reduce drafts, moisture, dust, pollen and noise.
Energy-efficient windows use at least double panes, with protective coatings and improved frames, to help keep heat in during winter and out during summer. Awning and casement styles often close tighter than sliding types.
Water vapor condensation is a threat to the structure of a house, regardless of climate.
Because an energy-efficient home is tightly sealed, controlled mechanical ventilation is needed not only to reduce air moisture infiltration, but to prevent health risks from indoor air pollution.
Heat or energy recovery ventilators salvage energy from the stale air exhaust and transfer it to fresh air entering from a heat exchanger.
Heating and Cooling
Airtight homes require relatively small heating and cooling systems. Generally, a heat pump is more efficient than separate heating and air-conditioning systems.
In addition to using less energy, energy-efficient systems are engineered to be quieter, reduce indoor humidity and improve the overall comfort of the home. When properly installed into a tightly sealed home, the equipment won’t have to work as hard.
In warm climates, light-colored exterior siding and roofing can reduce cooling requirements by up to 15 percent. Carefully selected and placed vegetation lessens cooling and heating loads in any climate.
Although higher-efficiency appliances often are more expensive to buy, operating costs usually are lower. That will add up to savings over the life of the appliance—and is especially important for water heaters, clothes washers and dryers, dishwashers and refrigerators, which are used often.
All major appliances are required to display an EnergyGuide label. Read it carefully to determine which model is most efficient.
Appliances that also have an Energy Star label exceed the federal government’s minimum efficiency standards.
Make your home even more energy efficient by looking for the Energy Star label when shopping for electronics.
Before building a home, carefully evaluate the site for optimum orientation.
If you live in a climate that requires heating most of the year, face the windows toward the sun. If you live in a climate more dependent on cooling, position the windows away from the sun.
Although not factored into Energy Star certification, house size matters. The smaller the home, the less energy is needed to heat and light it. n
Because energy-efficient homes require less money to operate, many lenders offer energy-efficient mortgages. They typically have lower points and allow the borrower’s debt-to-income ratio to be stretched.
Get the Ultimate Home Assessment
Does your existing home have drafty windows and doors, and rooms that are too hot or cold? Do you have high energy bills?
Installing replacement windows, a new heating or air-conditioning system, or more insulation may fix part of the problem. But for a truly energy-efficient home, greater comfort and lower utility bills, take a whole-house approach.
Using state-of-the-art equipment, a contractor certified to Building Performance Institute standards will evaluate all components of your home:
- Exterior. Inspects for moisture, proper attic and crawl space ventilation and window inefficiencies.
- Interior. Inspects for moisture, proper room ventilation, air leaks and insulation levels.
- Attic. Inspects insulation levels and ventilation.
- Crawl space and basement. Inspects for moisture, insulation levels and air sealing.
- Combustion safety. Tests for efficiency and any natural gas leaks or gaseous toxin levels.
- Blower door and duct blaster tests. Measures the volume of air leaking from your home and through your ducts, and helps identify locations of leaks.