If your house is like mine, it is an inefficient envelope that loses heat through windows, walls, roof and basement. According to the Maine Climate Council’s “Maine Won’t Wait” executive summary, given that 72% of a building’s energy is devoted to heating it, energy loss is a big problem in Maine, where winters are cold and long.

Fortunately, there are a handful of local organizations that are focused on promoting low-energy building solutions, the nonprofit PassivHaus Maine among them.

Freeport residents had the opportunity to learn about energy-efficient construction at a lecture sponsored by the Freeport Sustainability Advisory Board in late January. Naomi Beal and Tugba Gurcan, both of PassivHaus Maine, were the guest speakers.

PassivHaus is a global institution that certifies buildings that are net-zero, or energy neutral, meaning they require almost no energy input to heat and operate. According to Beal, this can be achieved by installing triple-glazed windows, excellent insulation (R-40 to R-60 for walls, R-60 to R-90 for roofs and R-30 to R-50 for slabs) and extremely efficient heat-recovery ventilation systems.

As one would expect, energy neutrality is more easily met in new buildings than in existing ones.

“Barriers to retrofitting include high cost of remodeling, limited availability of trained construction workers and poor access to low-carbon products,” Beal said. On the flipside, buildings retrofitted to PassivHaus standards have much lower energy costs, use fossil-free systems (such as solar arrays, windmills, heat pumps, geothermal systems, etc.), are resilient in extreme weather and use materials that are healthier for the people who occupy them.


“Once retrofitted,” Gurcan said, “we see an 85% reduction in energy use.”

In addition to efficient buildings, Beal and Gurcan spoke about the need for people to be efficient users.

“In the winter, wear a sweater while in your home instead of setting the thermostat at 78 or 80 degrees Fahrenheit,” Gurcan said.

“You can also take shorter, less frequent showers,” Beal added.

PassivHaus Maine anticipates that by 2050, 80% of Maine’s residential buildings, or 480,000 units, will be “existing stock” that will need to be retrofitted to curtail energy loss. Currently, only 150 homes are expected to get winterized to meet PassivHaus standards this year (a total of 750 Maine homes are weatherized each year, though not all achieve PassivHaus standards). Retrofitting efforts will go a long way in helping Maine achieve its goal of reducing 80% of carbon emissions by 2050 and a potential scenario to retrofit 500,000 units by 2050 in order to meet “Maine Won’t Wait” carbon reduction goals.

PassivHaus buildings abound throughout the world. They come in all shapes and sizes, they use a great variety of construction materials, and they range in size from single-family homes to large institutional buildings. Freeport Sustainability Advisory Board’s lecture on PassivHaus building can be viewed at youtu.be/qZ5NretmAxI.

“Freeport has a remarkable history of taking a leadership role in new building approaches,” Beal said. “Our town boasts the first Silver LEED home in the USA, the first gold LEED home in New England and the first PassivHaus high school in Maine.”


For those interested in building or remodeling using the PassivHaus standards, the organization has a roster of trained builders and material suppliers that is shared with the public. It also facilitates energy audits for existing buildings. For more, see passivhausmaine.org.

As I sit here in my house, watching the smoke spew out of our chimney and feeling the cold air drafts around our windows, I’m getting ready to call PassivHaus for an energy and retrofit audit as soon as I type the last word.

Valy Steverlynck is the co-chairperson of the Freeport Sustainability Advisory Board and a member of the RSU5 Sustainability Committee.

Editor’s note: This article was corrected on March 2, 2022 to clarify that 25,000 represents Passivhaus’ potential scenario to retrofit 500,000 units by 2050 in order to meet “Maine Won’t Wait” carbon reduction goals.

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