Minneapolis leaders want to add new requirements for anyone who sells an old home in the city that would require drilling a hole in a wall to check the insulation and using a special fan to see if the building is airtight.

The reviews by outside evaluators would give home buyers more information on how much energy is leaking out and help meet the city's goal of fighting climate change through a more energy-efficient housing stock. A related proposal would require landlords to disclose average energy costs to prospective renters.

"The city really wants to make some headway in terms of fossil-fuel emissions," said Council Member Cam Gordon, a cosponsor of the plan. "And with our cold winters … I think that the energy that goes into heating homes is a major contributor."

The still-evolving proposal has already run into opposition from real estate professionals, who say it will add hundreds of dollars to the cost of selling a home in Minneapolis with little benefit. "Although I'm all for energy improvements, why does the city of Minneapolis feel they have the right to invade the sanctity of my walls?" asked Stephanie Gruver, a real estate agent with Re/Max Results, who mainly sells homes in north Minneapolis. "Cutting a 2-inch hole in my 1928 hand-plastered walls is going way too far."

The energy analysis would be tacked onto a basic evaluation already performed on all houses sold in the city, which is now largely a visual inspection. Realtors and evaluators say it would more than double the cost that sellers pay for that Truth in Sale of Housing report, already upward of $200.

"It's going to be negatively impacting the real estate transaction between a buyer and seller … potentially putting Minneapolis homes specifically at a disadvantage," said real estate agent Shae Hanson, until recently chair of the government relations committee for the Minneapolis Area Association of Realtors.

Mike Childs, field supervisor at the Center for Energy and Environment, conducted a blower-door test

Other cities, including Portland, Ore., Austin, and Berkeley, Calif., require energy audits on homes being sold, according to the Center for Energy and Environment (CEE), a nonprofit organization advising the city. Each program is different — some rely on energy bills — and CEE representatives said it is not clear which other cities have requirements like those proposed in Minneapolis.

The proposal emerged from the city's 2013 Climate Action Plan, which aims to help 75 percent of the city's homeowners "participate in whole-house efficiency retrofit programs by 2025."

The precise language of the change, which would take effect in 2020, has not yet been released; it will be unveiled at a City Council committee meeting Jan. 28. In the meantime, city officials have been gathering input from real estate agents, evaluators and others — including at an event at City Hall on Monday evening.

The blower-door test involves removing air from a house using a special fan attached to a door, then determining whether the structure is leaky. The hole in the wall to check for insulation would only be required on homes built before 1980, and the hole could be sealed with a plastic plug.

"A lot of the information is great … we'd love to get it out there," Eric Myers, director of government affairs for the Minneapolis Realtors' association, told city officials. "But I can't see past the burden for some buyers. I can't see past the burden for some sellers."

Insulation checks and blower door tests are currently offered through Home Energy Squad visits, which are performed by CEE and subsidized by local utilities and some cities.

CEE staff at Monday's meeting said drilling a 2-inch hole to check for insulation is preferable to using infrared cameras because it shows how much insulation could be added. Energy bills are also not an ideal measurement, they said, because they vary widely.

"Your energy usage doesn't tell you how to improve the home, and it doesn't tell you why it's high," said Isaac Smith, CEE's residential program development manager.

The people who compile the city's Truth in Sale of Housing reports, who are independent evaluators, expressed concern about drilling holes in homes.

"We punch through and hit an old wire … it's our insurance and our tail," said evaluator Mike Moser. "The city doesn't underwrite that for us."

Moser also said the blower-door test will take more time than the city anticipates, adding cost.

Gordon, who is co-sponsoring the measure with Council Member Jeremy Schroeder, said he appreciates concerns about the drilling being invasive. But he added that he hasn't noticed the hole drilled into a closet in his home for an energy audit.

"The idea is it's as gentle a touch as we can to get some information that will be valuable," Gordon said. "Certainly if you find out there's no wall insulation anywhere in the house, that could be really valuable information."

Eric Roper • 612-673-1732