Building Homes for a Greener Tomorrow

There’s nothing gothic about the net-zero home of environmental reporter Sam Evans-Brown and his wife, but rooftop solar panels and electric meters that run backward might be new American traditions for which we can all take a stand.

I grew up in a 1950s Dutch Colonial that lacked a working furnace until I was in middle school. I remember when my brother and I were small, we would take a bath on Sunday night and then run back downstairs to the kitchen so that we could get dressed next to the wood stove. Even though the bathroom was above the kitchen and there was a hole in the kitchen ceiling that was meant to draw heat upstairs, it was never warm up there. There was an extended period somewhere around third grade where I only wore sweatpants in the winter because in the morning my jeans were unreasonably cold against my legs.

When we visit my parents, my wife and I will spend the night in my childhood bedroom and even now, with a functioning central heating system, frost accumulates on the inside of the windows. If there’s no fire in the stove, I leave my coat on in the house.

So perhaps you can understand why it’s hard for me not to evangelize for our current home.

On Christmas day of 2015 (due to a failure of planning on my part), we moved into a brand-new, super-energy-efficient home. Our walls have more than double the insulation required by the state’s building codes, and the tiny cracks between the plywood sheathing have been sealed so carefully that only one-seventh as much air is able to creep inside. Last winter — which was, I will allow, freakishly warm — we heated the house with less than one cord of wood. A heat exchanger constantly pumps stale air out of the house, extracting the heat from it and using that to pre-warm the fresh air that it pumps in.

Once the house is warm after my wife or I start a fire in the evening, if we (foolishly!) put more than two logs into the stove at a time, it can quickly get to over 80 degrees inside, even when it’s in the teens outside. We let the fire die out once we go to bed, and don’t start it up again until we get home from work the next day. If the day is clear and the sun is able to stream into the six windows that we arrayed along the south-facing wall of the house, it will be around 60 degrees when we get home. If there are clouds, it might be closer to 57. If we travel, I tend to leave the heat off.

Even after a week away in the dead of winter, I’ve never seen the house get any colder than 48 degrees, and even then a few hours before we get home I can use my smartphone to turn on the cold-climate air-source heat pump — an electric heat source that works much like your refrigerator, except backwards, and is two to three times more efficient than baseboard electric heat — and, by the time we walk inside, the house is back to a comfortable temperature.

The house requires no fossil fuels on-site. We cook and heat our water with electricity. We dry our clothes outside or by the wood stove. During the day, a 4.3-kilowatt solar array feeds power out onto the grid, and when we come home at night, we rely on the grid to power our lights and appliances. I specced out our solar array before I was sure how great our electric need would be, and after a year, we’ve exported nearly twice as much energy onto the grid as we’ve imported back into the house.

This means that our house is “net-positive”; it generates more electricity than it consumes.

“You don’t have to sacrifice aesthetics or even affordability for energy-geek accolades,” says my wife, Aubrey. “I love, for instance, that the extra insulation allows for extra-wide windowsills for plants. I love that I can sit at the kitchen table and almost feel like I’m outside because so much light comes in, especially in the winter.”

This philosophy extends beyond the walls of the house. “We bought property close enough to bike to work, left space for vegetable gardens and seeded with wildflowers instead of grass,” Aubrey says.

The net-zero Canterbury home of Ruth Smith and Beth McGuinn shows how technology blends with the rustic life.

I love our new house. It’s open, bright and airy. It stays warm in the winter and cool in summer. It is incredibly inexpensive to operate and was affordable to build. It’s small and cozy, but fits all our friends when we invite them over. It has space for bikes and skis and tools, and will have space when our family begins to grow. I love our new house. I love it.

And we’re not alone in our delight.

“We’re really not in touch with the weather,” says Millie Mugica, speaking with the same sort of happy amazement we have become accustomed to adopting when describing our house. Mugica’s home in Hollis is one of only a handful in the state that was a certified “zero” on the Energy Star Home Energy Rating System (HERS) scale, meaning it should produce as much energy as it consumes. (Ours clocked in at 23. A standard home gets a 100.) She says she will find that on hot summer days the family will be inside, comfortable, “but then you look at the thermometer and you’re like ‘jeepers, it’s hot out there!’”

The extra insulation means these homes are quiet. One place where we did splurge was on triple-paned, German-manufactured windows. While they can swing wide open on summer nights to let in the cool air, they are also exceptional at keeping everything that is outside out. My wife and I own one of the (now infamous) TDI Volkswagens, and even with its distinctive diesel growl, I often don’t notice when she has driven up the driveway and parked a mere 15 feet from our front door.

“I’m a birdwatcher, and I missed hearing the birds,” says Mugica. Somewhat bewildered, she wound up buying an indoor-outdoor speaker designed specifically to bring the sounds of the birds into their super-sealed house.

It also doesn’t hurt to be paying next to nothing for heat, light and water. Early on, before their 10-kilowatt solar array had been switched on, Mugica’s husband Gig Walsh says they got one bill for $144. But soon, all their electric bills were coming in at the minimum amount. “I don’t even really keep track of it anymore,” he says.

Indeed, one of our party tricks is to pull out our electric bill, which is the $10.27 minimum every month, and tell people that’s all we pay in utilities.

But as an environmental journalist, I’ve become vigilant about not green-washing away the impacts of proposed solutions. To build a home, trees have to be felled, land has to be cleared and resources consumed, even when that finished home produces energy as well as consumes it.

Evans-Brown warns that it’s possible to make things too warm if they don’t moderate the number of logs tossed into their high-efficiency fireplace.

Even the term “net-zero building” is one that is strangely ill-defined when you dig into it. “It’s a nebulous term,” says Bob Irving of RH Irving Homebuilders, the super-insulated home builder who built Mugica and Walsh’s home as well as mine.

The same house that is net-positive when my wife and I are living in it may not be if a family of five with a couple of 72-inch flat-screens were to move in. Brad Liljequist, director of net-zero energy for the International Living Future Institute, oversaw the development of a 10-unit townhouse project in Washington. The condos are all essentially identical, but only half are netting zero because of the different lifestyles of the inhabitants. “The reality is that they’re all incredibly efficient homes, and at a certain point, if they’re slightly over or under, the meta-message is that these are amazing homes that are hardly using any energy,” says Liljequist.

More to the point, whose definition of net-zero are we using? Our house is primarily heated by a wood stove, which emits harmful particulate matter and requires the taking of the occasional tree. The Living Future Institute doesn’t allow any combustion in the net-zero buildings that it certifies. “There are a couple of rules that we like to apply to our thinking, and one is, ‘What if everybody did it? What if everybody used a wood stove to heat their home?’” says Liljequist.

But I personally felt uncomfortable relying on the grid for our heat. While our solar panels may power our heat pump during the day, if we turn it on in the evening, then the electricity powering it will come, at least in part, from a fossil fuel-fired power plant. We opt to mostly use our wood stove, which is one of the more efficient and clean-burning on the market. “Unless you’re a hermit in the woods, there are drawbacks to every kind of energy,” says Ruth Smith, who estimates it takes about three cords of wood to heat her home in Canterbury. For the record, Smith considers hers to be a net-zero home as well.

In theory, you could take any conventionally designed building (note: “conventional” is a pejorative term in net-zero circles) and turn it into a net-zero building by converting it to all-electric appliances and installing scads of solar panels to offset the monstrous usage that may entail. Especially as renewable energy gets cheaper, this is the kind of outcome that causes efficiency devotees to toss and turn in their beds at night. “It’s a potential problem, but I’m not seeing it on the ground yet,” says Liljequist.

What’s more, the whole premise of a net-zero building rests on an institution (the electric utility) that has some ambivalence towards the idea. Net-zero buildings rely on net-metering — a policy that allows solar owners to roll their electric meter backwards whenever they are generating more than they are using. This means you can use solar energy generated in August to pay for grid power in February. This policy has come under siege all across the country in recent years, with utilities arguing that if every customer zeroed out their electric bill, no one would be left to pay for the grid.

If the practice of letting you bank solar credits from month to month were to change substantially, the very concept of being able to “net zero” your utility bills could go with it.

But as fuzzy a term as net-zero may be, it’s also a powerful idea that attracts prospective home owners to a set of better building practices. “You know, at a meta level, net-zero energy is a little bit of a Trojan horse to engaging people in a conversation about deep, deep energy efficiency and for getting renewables into the system,” says Liljequist.

Despite the evangelizing of those of us who live in these homes, using more efficient building practices does not seem to have penetrated into the mainstream. Smith says she knows a couple — one of whom owns his own business and is doing just fine for himself — who are just beginning to build a new home, and when she asked them how they were planning to make it more efficient, they didn’t have an answer. “Come on guys!” says Smith, exasperated, “What are you thinking?” These days, whenever I pass a construction site, I take note of how the building is being assembled, and very rarely are they sporting extra insulation.

In part, this is simply due to higher upfront costs. I can testify to the fact that money rushes from your bank account with terrifying speed and regularity when you’re building a home. What’s more, the most exciting items for most homeowners to splurge on are the ones they can imagine themselves using each day. In this way, if it comes down to a trade-off between another 4 inches of foam on the outside of your walls and that fancy two-sink, marble bathroom vanity you’ve always wanted, the insulation tends to be the first to get axed. That the extra insulation will pay for itself in 10 years feels like a very far-off prospect when you’re writing checks to the contractor.

Bob Irving says controlling these upfront costs has been his perennial challenge. “I’ve always wanted to build simple, affordable houses, and it’s been frustrating me for 45 years.”

What will it take for better building to hit the mainstream? “If I knew, I would tell you,” says Irving, but he thinks the trick will just be to get more companies into the game, trying new things. “If more builders get into this, they will have different cost structures,” he says. Maybe what it will take is getting the cost structures of McMansion-style developers excited about the net-zero concept. Who knows.

If more builders are going to adopt these practices, then it seems likely that change will come — as it so often does — from the west to the east. The state of California has mandated that all new residences be net-zero energy by 2020. “In terms of code, we see some leading jurisdictions out there, paving the way,” says Liljequist. Washington, DC, has an energy plan that he describes as a roadmap to eventually getting the entire city to net-zero energy.

Things change slowly, but change they do. It seems that, every time I turn around, there’s a new contractor touting an efficient building philosophy. Bob Irving says that, after years of struggling to get the word out, demand for these homes seems to be on the rise. His small crew finished five projects this past year, up from an average of two in previous years. He says he’s considered pulling his advertisements because he already has too many leads.

“I kind of think of our house project as a systems project,” says Aubrey. “What can we afford, which aspects will be most mutually beneficial for our personal well-being as well as that of society and our local ecology, and what new ideas can we try out or model so that other people might consider their housing choices differently.”

Smith, who has lived in her house for 10 years, and has already been interviewed for two magazine articles and one film, is hopeful that soon there will be more spokespeople for net-zero buildings in the state. “My goal would be for people to just be more thoughtful and knowledgeable when they build,” she says, “and for it not to be weird.”

It may still be weird for some time yet. Later this winter, a local teacher is planning to bring a gaggle of high school science students to our house equipped with a thermal imaging camera to see how different it is from a conventional home. They’ll ogle the deep windowsills that our 10-inch-thick walls create and marvel at the shiny solar panels. With any luck, maybe some of them will be a bit more thoughtful when they build their own homes.