Making buildings greener will be a monumental task for Minnesota

Katie Jones' new home has a secret hidden in the walls.

The house being constructed in Uptown Minneapolis includes triple-glazed windows and eventually, solar panels. Instead of using traditional foam insulation, Jones and her husband, Peter Schmitt, opted for bales of straw. They have the benefit of locking carbon in the plant material in the walls, and out of the atmosphere.

"Someone's got to try new things, and why not us?" Jones said.

Jones and Schmitt, who both work in clean energy, have spent significant time and money to ensure their new home won't contribute to the emissions driving climate change. Not every homeowner has the resources to do something similar, putting pressure on Minnesota to close the gap and hit new, ambitious goals for reducing greenhouse-gas emissions from all kinds of buildings.

In the state's Climate Action Framework finalized last month, DFL Gov. Tim Walz's administration has set the goal of slashing emissions from existing buildings by 50% in 13 years.

"That's an aggressive goal," said Richard Graves, director of the Center for Sustainable Building at the University of Minnesota.

Cutting those carbon losses from gas appliances or poor insulation could pay huge dividends. State modeling for the Climate Framework showed that better building standards, improving older structures and broader uptake of electric appliances scored in the highest category of emissions reductions, with the potential to avert more than 100 million tons of carbon dioxide from entering the atmosphere by 2050.

Federal funding will help. Rebates on heat pumps and other home electrical fixtures are a part of this year's Inflation Reduction Act, and $3.5 billion sent to bolster home weatherization programs was included in last year's bipartisan infrastructure law.

The task still won't be an easy one.

Consider one of goal in the Climate Action Framework: weather-proofing a quarter of low-income homes across Minnesota by 2030. According to 2020 census data, that's about 123,000 homes in a small slice of existing housing.

At the same time, a fight has already broken out about whether to update the state's decade-old energy codes for duplexes, triplexes and single-family homes.

Existing homes are an often-ignored place to reduce greenhouse gas pollution, Graves said. Emissions can be reduced by sealing the "building envelope" that retains heat in the winter and cooling in the summer — everything from the walls to windows to ceilings, he said.

"Once you build your building, you're not going to go back and change those," Graves said.

So policymakers have recognized the need to bolster help for homeowners to retrofit their properties.

Kevin Lee, deputy commissioner at the Minnesota Department of Commerce, said the recent federal funding will be a significant help in this area. Commerce runs the state's Weatherization Assistance Program, aimed at lowering energy bills for low-income Minnesotans.

Weatherization work has previously been underfunded — a 2019 report from a work group convened by state legislators concluded that at the rate of funding then, it would take 291 years to work through all the homes that were eligible for the state program.

Lee also said that there are many homes that can't be weatherized because of roof damage, mold, asbestos or some other disqualifying condition.

In the last legislative session, Commerce tried but failed to persuade lawmakers to provide more funding to help the owners of these already-damaged homes.

"I can't speak with certainty about what will happen next session, in January, but I think it's fairly likely these issues will come up again," Lee said.

Upgrading buildings isn't only about older homes. Right now, new multifamily projects are still overwhelmingly using natural gas for heating and cooling, Graves said.

"All that stuff in 13 years needs to be retrofitted" to hit the state's greenhouse-gas reduction targets, Graves said.

In new construction, some of the biggest gains can be made in raising the minimum energy efficiency standards in building codes. Minnesota is still operating under model codes that came out in 2012.

Homebuilder groups counter that these provisions raise the cost of housing in a time when inflation is already putting home ownership out of reach for many.

The Department of Labor and Industry is reviewing 2021 updates to energy and insulation standards for commercial structures in Minnesota, which include both businesses and larger apartment buildings. It has not yet decided whether to update the residential code, which covers free-standing houses, townhouses, duplexes and triplexes.

The new model standards would raise insulation requirements significantly, said Patrick Huelman, an associate extension professor and cold-climate housing coordinator at the University of Minnesota. This includes the requirement to wrap insulation on the outside of a building before cladding it, which Minnesota effectively stripped from the 2012 code before adopting it, Huelman said.

He acknowledged that builders are struggling to construct more affordable homes, but added, "Our new homes are still using far more energy than they could or should."

Nick Erickson, senior director for housing policy for industry group Minnesota Housing First, argued that homes in Minnesota are already the most energy efficient in the country. That's based on scores from the voluntary Home Energy Rating System.

"As we approach even more stringent energy standards, it prevents people from affording to buy a home," Erickson said.

But Elizabeth Turner, who consults and designs efficient homes at her Minneapolis firm Precipitate Architecture, argued that the industry has been able to absorb other price shocks.

"It's important to make sure that people can afford places to live," Turner said. But she added that when lumber prices increased dramatically, "we figured out a way to keep building."

For motivated homeowners who want to be as close to carbon-zero as possible, things can get expensive quickly.

Jones said she didn't know the exact cost to date for her straw-insulated house, but acknowledged that she and her husband had "blown through" their budget.

The cost came partly from code officials' fear that the walls could fail if the straw got too wet. The same thing actually happened to a straw-stuffed home on Lake Street in Minneapolis two decades ago, with the house eventually being condemned and torn down, the Star Tribune reported in 2003.

"We were the first ones to have done it in this city in a long time," Jones said. "It took a lot of our architect's time to convince the building officials this is legit."

That architect is Turner, whose firm also works on larger affordable housing projects, like the 82-unit Verdant building in St. Paul. Precipitate employs passive building, which means using air sealing, heat pumps and other measures with a goal of cutting 80% of the energy demand from a traditional build.

Except for the most motivated homeowners, like Jones, it might be hard to sell top-of-the-line green features to house owners, Huelman said. But other clients see the benefits more easily.

"Affordable housing developers will own the building for decades," Turner said. "They will see the payoffs. It makes financial sense."

Across the many firms and contractors in the construction industry, it takes time to push the adoption of new methods or new materials, Huelman said. Contractors not only have to learn how to install a heat pump, they have to justify the cost to a customer, he said.

Turner, for her part, now has a broad team of contractors to help make green building designs a reality. But that's a new phenomenon.

"Five years ago, that was not the case," she said.