1 of 13
Spenser Heaps, Deseret News
Martin Fragoso Villegas works on building a zero energy ready home in the Treseder at Little Cottonwood development in Sandy on Friday, Aug. 12, 2016. The development's model home, pictured in background, is featured in the Parade of Homes.

SALT LAKE CITY — New building codes approved by state lawmakers this past session put Utah among only 10 states in the country where energy ratings may be offered for would-be homebuyers.

The Home Energy Rating System, or HERS Index, gives a numerical score to homes for energy efficiency based on multiple construction factors such as exterior walls, ceilings, roofs, heating and cooling systems, and windows and doors.

The lower the score the better, but the U.S. Department of Energy said the typical resale home on the market today lands at about 130, while an average new home scores at 100.

A home with a score of 70, for example, is 30 percent more energy efficient than a typical new home built today, according to the federal agency.

"An energy-efficient home will save homeowners money every month,” said Kevin Emerson of Utah Clean Energy. “That’s why we advocated at the Utah Legislature for the new energy rating index to become part of Utah’s updated energy code; now buyers will know what kind of energy use to expect, like considering the fuel economy label on a new car.”

The new law establishes passing scores for new homes in three main climate regions of Utah: 65 for the St. George area, 69 for the Wasatch Front and 68 for Logan and Park City.

"Owning a home is about a lot more than a mortgage. Energy-efficient homes will be affordable for years to come due to low energy costs, and they’re more comfortable,” sad Steve Baden, executive director of Residential Energy Services Network, which developed the index. The network is a national nonprofit organization dedicated to helping make homes more energy efficient.

Baden noted that Utah is emerging as a national leader for its emphasis on energy-efficient homes.

“In 2015 alone, 1,498 new homes built in Utah received a HERS Index rating with an average rating of 61," he said. "This represents a home being 39 percent more efficient than a home built as recently as 2006 and 69 percent more efficient than a home built in the 1970s.”

Utah Gov. Gary Herbert's Clean Air Action team organized two years ago identified moving to more energy-efficient building codes as one of the top ways the state could address its persistent air quality problem.

With Utah's population to nearly double by 2050, state air quality regulators predict homes will replace cars as the dominant source of pollution.

Advocacy organizations like Utah Clean Energy pushed for the adoption of the latest building codes for new residential construction, imploring the state to require builders to make homes as energy efficient as possible.

Glenn Hoggan with Garbett Homes said understanding the Home Energy Rating System Index is an educational process that will catch on with the public as it becomes more prevalent among homebuilders.

"Consider it the miles per gallon for your home," he said. "People can more easily understand energy efficiency if they think about the miles per gallon they can expect to get out of their home in terms of savings on utility bills."

James Jonsson of Ivory Homes — the state's largest builder — is incorporating components of the index in some of its new housing stock.

"Energy efficiency is a selling feature," he said.

Twitter: amyjoi16