New homes ITP and OTP strive for greater energy efficiency

One of Chamblee’s newest homes is pushing the envelope of energy efficiency. Twice as insulated, six times more airtight and almost 40 percent more energy-efficient than a typical Georgia home, this contemporary house is the fourth Zero Energy Ready Home built in Georgia by Athens-based Imery Group, which goes far beyond adding basic eco-friendly features.

To be certified as Zero Energy Ready by the U.S. Department of Energy, a home must be “so energy-efficient, that a renewable energy system can offset all or most of its annual energy consumption.”

“There’s no one thing that makes a house Zero Energy Ready,” said Luis Imery, founder and CEO of Imery Group, a custom home builder. “It’s how we put things together and make them work that creates that performance.”

Dollars and cents

To quantify a home’s energy efficiency, the DOE uses the Home Energy Rating System (HERS). Just as miles per gallon ratings allow consumers to estimate how much it will cost to use a car, HERS gives consumers a way to estimate how much it will cost to live in a home. The lower the HERS index, the more efficient the home and the lower its utility costs.

According to the DOE, the national average HERS score is 100 for a new home and 130 for a resale home. For example, the 3,764-square-foot home that Imery Group completed in 2016 in Chamblee’s Sexton Woods community has a HERS index of 54.

To Imery, buying a home without knowing its HERS index is akin to buying a car without knowing its fuel efficiency. Imery advises house hunters to consider what they will be paying on a mortgage and what they anticipate paying for power and utilities on a traditionally built home and then compare that to the mortgage, utilities and power costs of more energy-efficient homes.

Because power costs increase over time, Imery believes consumers leave money on the table when they choose a home that comes with a smaller price tag, but a higher cost of ownership. A person buying a $230,000 Zero Energy Ready Home would likely pay less over the lifetime of that home than a person buying a similar $200,000 home, Imery said. His custom houses range from the $200,000s to over $1 million, and the Chamblee home had a budget in the mid-$600,000s.

Imery Group was the DOE’s 2016 Grand Winner for Innovation in Custom Homes for a Roswell home with an average estimated energy bill of less than $17 a month. Homeowners save $1,896 annually compared to the energy bill of an average home.

Building for efficiency

Homebuilder Meritage has built tens of thousands of Energy Star-certified houses across the nation. To earn this certification, houses must meet guidelines set by the U.S. Environmental Protection Agency, including being about 30 percent more efficient than standard homes.

Stephen Haines, the Atlanta division president for Meritage, said Meritage homes average ratings between 50 and 60 on the HERS index, making them “40-50 percent more efficient to live in under the same conditions as an average house built in the year 2000,” the year the HERS index was established. Meritage’s homes range from $160,000 to more than $600,000 in 35 communities in Georgia.

To reach a high level of efficiency, Meritage builds thicker walls that hold more insulation, installs windows that transfer less heat, sprays foam insulation that allows in moisture but resists heat and employs Energy Star appliances and smart-water fixtures. Meritage also extends the insulation to the “outer envelope.” That means that instead of laying insulation on the floor of the attic like most houses, Meritage sprays foam insulation on the attic ceiling, encapsulating the air conditioning system. This saves Meritage homeowners the money most homeowners lose to indirectly conditioning their attics.

“We build [attics] more like a Yeti cup,” said Haines. “What that means is that the air conditioner is now performing in that conditioned space it provides. It operates much more efficiently.”

Attracting buyers

Imery Group builds custom houses for clients already interested in energy efficiency. Meritage, on the other hand, recently introduced “learning centers” to demonstrate the science behind energy efficiency and generate interest in its homes.

“Because the majority of what we do different is relatively invisible — behind the walls or a different material — the average consumer cannot experience it just by their sight,” said Haines. “We created learning centers to help educate them on why our science, our technology, is different than what they’ll encounter with the vast majority of any other homes.”

These centers, located in Meritage’s model homes, allow potential clients to experience the difference in Meritage’s construction and use of materials. For instance, by placing heat lamps behind both an up-to-code window and an insulated Meritage window, customers can actually feel the difference in the amount of heat transferred.

“In Atlanta, Energy Star homes are like iPhones,” Haines said. “I don’t know I need it till I see it.”