Proposed changes to Minnesota's building code that are meant to make houses safer and more energy-efficient have roused the ire of some local builders, who say the guidelines could significantly jack up prices of new homes.

At issue are a handful of energy upgrades that would require builders to increase the amount of insulation to basement walls and add fire sprinklers to every new house. Builders say the changes could add up to $20,000 to the price of a new house, a burden they don't think consumers are willing to shoulder in tough economic times.

"We're having a spirited discussion about what's best for Minnesota," said Pam Perri, executive vice president of the Builders Association of Minnesota (BAM). The trade group says the revisions could shrink its market by at least 20,000 prospective buyers.

Discussions have been under way for several months as part of a regular statewide building code update, which is derived from a consortium of international experts. The Minnesota Department of Labor and Industry is charged with guiding the rule-making process.

State building official Steve Hernick said there's general agreement on most aspects of the changes, including those that would reduce air leaks in homes, increase the quality of windows and improve ventilation. Those requirements will likely take effect sometime next year. Advocates say the updates could make Minnesota houses some of the safest and most energy-efficient in the nation.

The state "made some modifications that really improved the code," said Isaac Elnecave, a senior policy manager in charge of building codes for the Midwest Energy Efficiency Alliance in Chicago.

But debate rages over whether the guidelines would just over-insulate basement, or below-grade, walls. BAM contends there's no proof that increasing the amount of insulation in below-grade walls will offer a meaningful improvement in energy savings, and that the payback time could be more than 40 years.

Worse, the group says, requiring additional insulation will only increase the risk of moisture, which can jeopardize durability. BAM says the new Minnesota code doesn't take into consideration the extreme weather conditions Minnesota houses endure.

"How we build in Minnesota is different from how we build in Arkansas," said Perri. "We're not against more insulation; we're against construction practices that will impact durability."

Those concerns are based on a troubling number of moisture-intrusion problems in new homes that have resulted in costly and often difficult-to-diagnose water damage. Some have blamed the problems on moisture being trapped in the wrong places.

BAM is also vehemently opposed to a provision that requires all new single- and two-family houses to have fire sprinklers as is already required in two states. In a preemptive strike, Minnesota lawmakers last year passed a law banning mandatory sprinklers that was vetoed by Gov. Mark Dayton. A similar bill has made it through committee and awaits a floor vote in the House and Senate.

BAM says new houses are already safe because builders are required to install hard-wired smoke detectors on every level and in every bedroom, and that there's no data that show the sprinkler change is necessary.

"We do intend to fight the requirements -- not because we don't care about safety," BAM's Perri said.

The proposed sprinkler requirement already has widespread support from three of the state's largest firefighters associations. They say sprinklers save lives and are most affordable when installed when the house is new.

BAM says all of these changes could increase the cost of an average new house by 10 percent, or about $12,000 to $20,000. Elnecave disputes those claims, saying tweaks to the energy code alone will increase the cost of a new house by about $2,500. That's a "conservative" estimate, he said, adding that requiring a higher level of energy efficiency is much more cost-effective when new.

"It's much harder to fix a home and add insulation and new windows," he said.

Tom Brace, executive director of the Minnesota State Fire Chiefs Association, likens the cost of fire sprinklers to a carpet upgrade, estimating the cost at $2,000 to $3,000. "We are of the opinion that is the ultimate in fire safety."

While the Department of Labor and Industry drives the process, adoption of a new code doesn't happen without considerable input from those with a vested interest. And that means months of negotiations among builders, suppliers, government staffers and experts from the field.

Perri said that can make the code adoption process highly political. "Every manufacturer wants to get their product in the code," she said.

For example, Perri said that representatives from the big insulation manufacturers have been present at code hearings.

For now, the state is still receiving feedback about the proposals. Hernick said that while there's no firm deadline in place for implementation, the agency hopes to put together a draft rule in the next month or two before it goes through a comment and review process.

The goal is to come up with a draft that everyone can agree on to avoid a hearing before an administrative law judge. He said the state hopes to adopt a new standard that will go into effect next year. "We're still working," said Hernick.

Jim Buchta • 612-673-7376