Energy efficiency and green homes

Why should the home-building industry care about energy efficiency? Three reasons, say experts. The first: Because buyers care. They like saving money, and some choose to buy homes with the environment in mind.

An energy-efficient home is a well-built home, and contractors can actually save time and money along the way.

Second, an energy-efficient home is a well-built home.

Third, contractors can actually save time and money along the way. A new wave of communities now advertise “green” houses, many under the “Building America” program sponsored by the U.S. Department of Energy (DOE). Clarum Homes in Palo Alto, Calif., built the state’s largest zero-energy home community, Vista Montaña. Its trademarked “Enviro-Homes” provide more than $20,000 of added value to homebuyers through reduced utility bills, says John Suppes, vice president. Here are the top eight energy improvements that save money:

Where’s the air?

HVAC placement is vital for energy efficiency, according to the National Association of Home Builders Research Center’s online guide, ToolBase Services. Equipment and ductwork usually end up in attics, garages and crawlspaces where insulation levels are R-4 or R-6. (See “Know Your R-Values.”)

Instead, locate as much heating and air conditioning equipment as possible in conditioned spaces, where insulation is R-15 to R-30 and higher. That way, the systems will be up to 35 percent more efficient. And if the ducts leak—at least they leak where it helps!

Insulation alternatives

There’s more than one way to insulate a house and dozens of new insulation products with super-high R-values deliver advantages in installation and cost. As an alternative to fiberglass, batts made of sheep’s wool and recycled denim, both safe to handle without gloves and considered “green” or environmentally conscious, are on the market. Sprayed foams and fibers work well, too, offering fast application and uniform coverage of stud cavities with the moist, sticky material.

“Cellulose foam seals every nook and cranny—great for new construction,” says Michael Buckley, engineering manager with energy-service company Noresco, Westborough, Mass.

Attics that breathe

Venting attics is crucial to letting air circulate and escape. “Even if it’s only 95 degrees outdoors, the attic can get as hot as 130 degrees,” says Noresco’s Buckley. “A gap along the entire ridge allows a lot of air to move, lowering attic temperatures by 20 degrees. That’s a big, big deal especially during cooling season.”

In addition to ridge vents, Buckley counts attic-intake vents, static vents, power vents and whole-house fans, helpful in lowering energy costs.

Fluorescent lighting with a twist

Today there’s another way to cut heat and energy: compact-fluorescent lighting, or CFL. “Compact fluorescent is the best today in terms of efficiency,” says George James, project leader for DOE’s Building America. Shaped like classic round bulbs or in mini-swirls and tubes, the lamps swap directly into standard fixtures and downlights. They typically last up to 10 times longer than incandescent bulbs and require 75 percent less energy.

Smaller skylights

Another product has gone compact: the skylight. New tubular kits use reflectors and optical materials to concentrate, bend and direct daylight as needed. Unlike typical skylights, these “daylighting systems” from companies such as Solatube capture more low-angle morning and evening light and move the light around angles and bends. Installation is simple, too.

Robotic control

Programmable thermostats like those from Honeywell lend intelligence to household heating and cooling. “You can set the cooling at 76 degrees when the house is occupied, and go back to 80 when unoccupied,” says Buckley. “It saves an immense amount of energy—up to 33 percent of heating and cooling costs—and the thermostats only cost $40 to $80.”

Seeing clearly now

Good windows are critical to energy performance, too. “Windows, doors and skylights contribute about 30 percent of overall building heating and cooling loads,” estimates James C. Benney, executive director of the National Fenestration Rating Council (NFRC), Greenbelt, Md., which sponsors labeling programs for windows. “Energy-efficient systems not only save energy and money, they make the home quieter and more comfortable.” Benney recommends looking for NFRC labels, found on all Energy Star-qualified windows. The labels tell contractors about resistance to heat, light transmittance, air leakage, condensation resistance and other key factors.

Door jambs and more

Just like windows, doors have NFRC labels, too. In addition, ToolBase describes a new product to improve a door opening’s overall efficiency. The new header design consists of foam insulation sandwiched between two web panels and provides more than doubled R-values with no additional labor costs—all from a single-piece unit that won’t sacrifice structural integrity. There are many more ways to improve a home’s efficiency. But with these additions up their sleeve, contractors will find better performance—and a bigger market—for the projects down the road.

Know your R-values

An R-value measures a material’s resistance to heat flow. In places of extreme heat or cold, insulation helps regulate indoor temperatures and reduces the size of the heating and cooling units needed. The U.S. Department of Energy (DOE) provides online recommendations by zip code for the R-value needed in a home.