The commission last month approved the new code on a 5-2 vote but will take a final vote after a public hearing Wednesday.
An ad hoc committee of the commission spent two years discussing the standards, which would require new homes to have 50 percent high-efficiency lighting, increased wall and water pipe insulation, improved duct sealing and third-party testing of energy efficiency.
The nonprofit Utah Clean Energy and other advocates contend the code would add less than $1,000 to a homebuilder's cost and would save a homeowner after paying a higher home price but lower energy costs an average of $175 a year over the life of a 30-year mortgage.
Taz Biesinger, executive vice president of the Utah Home Builders Association, disputes those figures, saying the added costs could be many times higher.
Even if the $175 a year were correct, he said, homeowners could reap half the savings by simply using energy-efficient light bulbs.
"It's a lot of effort," Biesinger said, "for virtually little return."
The standards are set forth in the 2009 International Energy Conservation Codes, which Utah already adopted for commercial buildings. For houses, the state uses the 2006 code.
Brent Ursenbach, a building inspector for Salt Lake County who served on the ad hoc committee, advocates the new standards.
"We're just saying, 'Let's not stay back three years. Let's get current.' "
If it takes a homeowner six to 10 years to recoup the extra upfront house costs through energy savings, he said, so be it. "A home is going to be there, in most cases, for 100 years," Ursenbach said Wednesday in a meeting with the editorial board of The Salt Lake Tribune.
"It's cheaper to do it right in the first place," said Sarah Wright, executive director of Utah Clean Energy.
But Biesinger argues the 2006 standards are already aggressive on energy conservation and have accomplished a lot.
"We don't oppose more energy-efficient homes, but we could require solar panels on every house and nobody could afford to buy them," he said. "We need to be smart about what we require."
A public hearing on proposed energy-efficiency standards for new houses is planned Wednesday at 9 a.m. at the State Office Building (behind the Capitol), Room 4112. After the hearing, the Uniform Building Code Commission will make a recommendation to the Legislature's Business and Labor Interim Committee, which is to consider the issue at its Sept. 15 meeting at 2 p.m. in Room 210 in the Senate Building.