Expert Advice

How to Design a Pretty Good House

Niftier than its tongue-in-cheek name suggests, the grassroots building standard launched in Portland balances cost and energy performance.

A modest 1,100 square feet and sporting Maine-milled cedar siding and rooftop solar panels, this York home, designed by Portland’s Caleb Johnson Studio, embodies several Pretty Good House principles.

ABOVE A modest 1,100 square feet and sporting Maine-milled cedar siding and rooftop solar panels, this York home, designed by Portland’s Caleb Johnson Studio, embodies several Pretty Good House principles. Photographed by Trent Bell. 

TEXT BY JESSE ELLISON

From our Fall 2021 issue

The concept of a “pretty good house” grew out of a “beer-fueled rant” at a Portland building-science discussion group a decade ago. But the ranter, Portland builder Dan Kolbert, says booze was actually beside the point. “We’re pretty good at ranting,” he says. And, at the time, he’d had it with the various costly rating systems that had him jumping through hoops to prove a house was “green” that didn’t always make sense. For example, he had a client who wanted to upgrade his house to meet rigorous Passive House energy standards, but “the only way to achieve it was to put an unjustifiable amount of foam insulation in the basement,” he says. “It seemed like we had an opportunity to talk about, ok, if you were to distill it down, what are you really talking about when you talk about a ‘good house?’”

The group came up with what architect Chris Briley, of Portland’s Briburn, calls “a common-sense approach to sustainable building,” a framework for achieving a practical level of performance in a durable, net-zero-energy-ready house that is adaptable to homeowners’ habits and budgets. In other words, a Pretty Good House. Palermo residential designer Michael Maines summarized the discussion in a blog post on greenbuildingadvisor.com, and, more than a hundred comments later, they realized they’d struck a nerve.

Maines and Cumberland architect Emily Mottram now host a nationwide panel discussion called The BS & Beer Show (“BS” stands for “Building Science,” of course) on Green Building Advisor that espouses the Pretty Good House approach; similar discussion groups have popped up around the country; and Kolbert, Briley, Mottram, Maines, and Steve Konstantino, CEO of Portland’s Performance Building Supply, are codifying the PGH ethos in a book for Taunton Press, scheduled for release in early 2022.

With insulation, air sealing, heat pumps, and a mechanical ventilation system, Portland’s Briburn architecture firm and Bowdoinham’s Emerald Builders turned a drafty old Falmouth barn into a highly efficient, healthy living space.

ABOVE With insulation, air sealing, heat pumps, and a mechanical ventilation system, Portland’s Briburn architecture firm and Bowdoinham’s Emerald Builders turned a drafty old Falmouth barn into a highly efficient, healthy living space. Photographed by François Gagné. 

In light of the United Nations 2018 climate-change report, which emphasized the building sector’s outsize role in the production of global-warming emissions, the PGH founders have placed new emphasis on reducing a home’s carbon footprint. But the bulk of their original principles has remained the same, as has their commitment to being an open-source, non-revenue-generating “non-standard,” espoused with humor not typically associated with environmental advocates. “One of our many jokes is, send us $50 and we’ll send you a pretty good plaque,” Kolbert says, a dig at performance-rating systems that dispense wall plates for meeting benchmarks. “Then there are all the people who argue about the name — they say it should be a ‘Really Good House.’ It’s a good way to filter out clients with bad senses of humor.”

So what makes a house “pretty good?” We present a pretty good list of pointers.

RENOVATE INSTEAD

“Now is the worst time in human history to be putting carbon in the atmosphere, so does it even make sense to build an incredibly energy-efficient house if it’s resource intensive in construction?” Kolbert asks. Maybe not. There’s a tremendous amount of energy and carbon already sequestered in existing structures, so an environmentally responsible renovation can be a lot better for the earth than building new. Konstantino is more blunt: “The greenest house is the one you don’t build.” Adds Briley with a chuckle, “and we’re all out of a job.”

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BUILD AS SMALL AS POSSIBLE

If you’re going to build, minimize your footprint. The PGH group recommends 1,000 square feet for one person, 1,500 for two, 1,750 for three, and 1,875 for four — targets that have been subject to strenuous debate. “We’ve gotten strong feedback from people who thought we were either way too big or way too small,” Maines says. “Almost nobody thought we hit it dead on, which probably means we did because it’s pretty balanced between the two camps.” But with more people needing home offices post-Covid, Maines admits, the numbers may need to bump up a bit.

FOCUS ON INSULATION AND AIR SEALING

“Nothing else matters if you don’t do a good building envelope,” Mottram says. Insulation and air sealing should be sufficient enough that heating and cooling systems can be minimal, lowering your utility costs and impact on the planet. Mottram recommends cellulose and wood-fiber insulation for their performance, modest carbon footprint, and relative affordability. “If you have to cut back, I’d cut back on square footage first,” she says. “Or don’t do a garage or granite countertops. You can always do those things later. But you’re never going to go back and pull out insulation.”

Designed by Briburn and built by Eastern Construction in Thomaston, this Bremen home is equipped with solar panels and a heat-absorbing vegetated roof.

ABOVE Designed by Briburn and built by Eastern Construction in Thomaston, this Bremen home is equipped with solar panels and a heat-absorbing vegetated roof. Photographed by Trent Bell. 

PRIORITIZE INDOOR AIR QUALITY

“I would say categorically that every Pretty Good House needs a mechanical ventilation system,” Maines says. “And the tighter the house, the more important it is.” These systems pull fresh air into a home and exhaust stale air, allergens, and pollutants such as CO2 and radon (a naturally occurring radioactive gas, prevalent in Maine, that can cause lung cancer). Of course, when the weather is nice, cracking windows also improves airflow, “but in Maine, that’s about two months of the year,” Maines says.

GO ELECTRIC

In the United States, burning gas is now a bigger source of climate-altering emissions than burning coal, and nearly a third of that gas is guzzled in homes and commercial buildings. To cut your consumption, opt for electric-powered air-source heat pumps for heating and cooling and an electric range, which is preferable to a pollutant-emitting gas unit. Ideally, you’ll generate all the electricity you need with solar panels, which pay off their carbon debt in two to four years. If you can’t plop panels on your roof — due to lack of southern exposure, for example — consider joining one of Maine’s burgeoning community solar farms, which allow members to tap into a renewable energy source and receive credits on their utility bills. To find one, visit communitysolar.energysage.com and type in your zip code.

This 1,000-square-foot cutie with two bedrooms and a single bath is one of 12 prefab Go Homes offered by Belfast’s GO Logic, which hews to strict Passive House energy standards.

ABOVE This 1,000-square-foot cutie with two bedrooms and a single bath is one of 12 prefab Go Homes offered by Belfast’s GO Logic, which hews to strict Passive House energy standards. Photographed by Brian Vanden Brink.

INVEST IN WOOD AND PLANT-BASED MATERIALS

In general, the more materials are processed, the higher their carbon footprint. So an all-wood house that meets minimum building codes “may be much better for the environment in the short term than a more energy-efficient one that uses high-tech materials,” Briley says. When possible, choose sustainably harvested, locally sourced wood and insulation made from cellulose, wood fiber, or other natural materials in place of rigid or spray foam.

Next year, Madison-based GO Lab will start making wood-fiber insulation, claiming to be the first company in North America to do so. To cut down on concrete, whose manufacture produces 8 percent of the world’s CO2 emissions, opt for a slab foundation over a full basement, or try Comfort Blocks by Saco’s Genest Concrete, which use less concrete.

JOIN A SUSTAINABLE COMMUNITY

Building a house that sits alone in the middle of the woods is a lot harder on the environment than one that’s plunked down in a subdivision that shares infrastructure, such as roads, broadband, electricity, and more. Mottram recently had a conversation with a builder who’d demoed a house, but only had to fill one dumpster with refuse: the rest was hauled away by neighbors for their own projects or to burn in woodstoves. Not to mention, she adds, one of the biggest contributors to global warming from the building sector comes from contractors driving to job sites each day. If you don’t build in the boonies, you’ll save those fumes.

There’s only a hint of Sheetrock in this fir-paneled bedroom in a new home Portland’s Kaplan Thompson Architects and Freeport’s Warren Construction Group erected in the footprint of an old summer place on Casco Bay.

ABOVE There’s only a hint of Sheetrock in this fir-paneled bedroom in a new home Portland’s Kaplan Thompson Architects and Freeport’s Warren Construction Group erected in the footprint of an old summer place on Casco Bay. Photographed by Irvin Serrano. 

And whatever you do, DON’T:

Get distracted by chasing points. “We used to joke that if you put in a bike rack, you get a LEED rating,” Kolbert says, referring to the global green-building rating system. “Then in the early days of Passive House, people were putting ridiculous amounts of insulation underneath their slabs because it juiced the numbers enough to get certified.” A PGH necessitates a cost-benefit analysis.

Go crazy with spray foam. It’s made from petroleum-based oil and its bubbles are composed of refrigerant, a potent greenhouse gas. “The more you use, the better your house will perform, and the worse it is for the environment,” says Maines, who limits it to basements, attic renovations, flat roofs, and other spots where existing conditions call for compromise.

Forget about moisture. Adding a rainscreen — an air gap between a home’s siding and water-resistant barrier — allows moisture to evaporate before it collects on cladding, causing mold and rot. “It’s probably the best thing you can do to make a house last longer,” Konstantino says.

Overcomplicate things. Elements such as dormers and bump-outs may slightly enlarge a living space, but they also create places for ice dams and air leaks to form, and complicate construction. Simple shapes are easier to seal and insulate, and require fewer materials and less maintenance.

Believe everything that claims to be “green.” Skepticism of “greenwashing” is at the core of the PGH concept. “Some things called ‘green’ may have a green element but holistically they’re really not,” Maines says. Take bamboo flooring — yes, the grass is regenerative, but it’s also highly processed and typically imported from China. Other products to be wary of: foil-faced bubble wrap “insulation” (Maines calls its R-value claims “ridiculous”), “insulating” paint, and anything that advertises “recycled content” — “it could be good, but it could be misleading.”

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