Rebekah and Stephen Hren took a 75-year-old house and turned it into a model zero-carbon home. Here’s how.
Diane Daniel | September 2008 issue
Rebekah Hren stands over the small desk in the bedroom she and her husband Stephen share in Durham, North Carolina, and powers up their Mac mini. She clicks straight to the local television station’s weather site and opens its up-to-the-minute DUALDoppler 5000 radar feature.
Rebekah isn’t concerned with whether she’ll want to carry an umbrella today. Instead, she’s deciding which appliances the couple wants to avoid, which windows and blinds to open and close at what times and how long a dish will take to cook in their solar oven. “Every morning we take stock of the weather and then do the windows and shades,” she says. “It doesn’t take long. You get used to it.”
Although the Hrens (pronounced “Rens”) live in the city, their 1,400-square-foot home isn’t connected to the power grid for now. Their energy comes instead from six 200-volt solar panels on the roof, generating 1.2 kilowatts of power. That’s not an awful lot of electricity, but then, the couple doesn’t need all that much.
Since Rebekah, 33, and Stephen, 34, moved to their Durham house two years ago, they’ve been on a mission to live free of fossil fuels, a goal that by their accounts they’ve come pretty close to achieving. “I think we’ve done a pretty good job,” Stephen says. “We cut about 95 percent of our non-renewable energy use.”
They didn’t reach that low level of consumption by buying a spiffy new high-tech “green” home, but by retrofitting an older house. “There’s almost no such thing as a new green home,” Stephen notes. “New homes require not only new materials, all of which are heavily energy intensive, but often new land and roads.”
The Hrens are part of what Stephen calls “a quiet revolution” in microgeneration, in which consumers produce their own renewable electricity. This change is fuelled not by off-grid homeowners but by those connecting to local utilities. The vast majority of solar installations in the U.S. tie into the conventional electricity grid, as the Hrens plan to do, so that any extra energy generated can be sent back to the grid and used by someone else.
But the Hrens have gone far beyond greening their home electrical system. Compelled by limited oil production, global warming and a sense that the developed nations as a whole, are wasting resources in every conceivable way, the young couple is among the earliest to adopt microgeneration techniques that reduce personal fossil-fuel use and the accompanying carbon dioxide emissions. “It is now possible to live a very good life using only renewable energy,” Stephen says.
The Hrens’ quiet revolution began in 2006, when they paid $150,000 for a well-worn two-story house built in 1932. Since then, with $40,000 (including foundation work) and tens of thousands more in sweat equity, they’ve transformed it into a carbon-free showcase. That’s not to say it could grace the cover of House Beautiful. But Home Energy? Absolutely.
The couple have chronicled the project in their recently published The Carbon-Free Home: 36 Remodeling Projects to Help Kick the Fossil-Fuel Habit. While the book, published by Chelsea Green, is presented as a how-to home manual, it’s really a lifestyle makeover guide, including chapters on food, landscaping, transportation and travel, along with appliances, refrigeration, hot water and heating and cooling. The couple relays technical information in a down-to-earth, conversational way, sharing many personal experiences.
For two days and a night I was Rebekah and Stephen’s house guest so I could see what it means to live “carbon-free,” using only sustainable-energy alternatives. I ate homegrown or farm-fresh meals, recharged my laptop with solar energy, showered with water warmed by a solar water heater and rode in a waste-oil-fuelled 1977 300D diesel Mercedes (which the couple, now on “car sabbatical,” has sold). I also availed myself of the “humanure” toilet, and was taught to sprinkle fragrant pine sawdust over my deposits. (There’s a flush toilet for modern-day traditionalists.)
By the end of my stay, Stephen and Rebekah had convinced me that carbon-free living is attainable if effortful. It also helps tremendously if you can live without air conditioning and do part of the reconfiguring work yourself. Stephen is a restoration carpenter and lately has been working with an edible-garden and landscape business. Rebekah, a licensed electrical contractor, installs solar systems and can do her fair share of plumbing. However, to the authors’ credit, more than half of the book’s projects require only basic skills or none at all, with some as simple as growing vegetables or sealing drafts.
I first heard about the Hrens, who live only a couple miles from me, when someone mentioned the rural home they built several years earlier out of cob, a traditional mix of clay, sand and straw, where they lived off the grid for six years. Through that massive DIY effort (done with many hours of help from friends and family), they developed their building skills. But this escape-to-the-country experience is also what prompted the two, who’ve been on a counterculture path together since high school, to return to urban living. Removed from family, friends and job sites, they were dismayed to discover that car travel offset their energy savings. As they write in their book’s introduction, “It was time to learn from our mistakes and move back to the city, a city that had oodles of existing houses just waiting for a good retrofit.”
On the morning I report for my sleepover, the first thing the Hrens do is show me to the sizable guest room, which has doors leading to a shared bathroom and a green-roof patio. I get a quick lesson in the six-month-old humanure system, which they stress is optional. “Some people are freaked out by it,” Rebekah says.
The setup, which works like a litter box, consists of a wooden bench holding a toilet seat half-filled with sawdust and next to that a container of more sawdust for replenishment. You do your business and cover it. The couple composts the remains in the backyard.
The neighbourhood the Hrens moved to, Old North Durham, is a hodgepodge of lower-income and middle-class homes, many built in the early- to mid-1900s, some restored. “One reason we picked our house is it had a big south-facing roof,” perfect for the solar panels, Stephen says.
Having grown up in nearby Raleigh, the couple gravitated to Durham several years after graduating in 1998 from the University of North Carolina at Chapel Hill. The city of 209,000, with its working-class past in textiles and tobacco, racial diversity (50 percent white, 40 percent black, 8 percent Hispanic), top-notch Duke University and high-tech centre, Research Triangle Park, is a magnet for liberal types who appreciate its scrappy attitude and affordable real estate.
The Hrens’ corner house on a busy thoroughfare is nearly surrounded by small apartment buildings that have attracted communities of Latino families and workers. At 6 a.m. most days, a cacophony of beeping horns rips through the stillness as workers catch lifts to their constructions jobs. In the evening, Mexican music blares from the parking lot across the street. “It’s not really your typical neighbourhood,” Stephen notes.
Today the sky is grey and the temperature is predicted to sink to an unseasonably low 72 degrees Fahrenheit (22 degrees Celsius), a drop of 16 degrees from yesterday. The house is still warm, so the windows stay open. The Hrens are planning to connect to the grid eventually, so they can feed power back to Duke Energy for credit. Any electrical production created by a system at a home, office or anywhere else that isn’t used by occupants can be fed “backward” through the utility metre and sold to the local utility provider. “The panels are just sitting there waiting to send power,” Rebekah says. “I feel so bad about wasting it.”
For now, they’re reliant on the weather. “If we get three or four cloudy days in a row we need to be careful, like we won’t open and close the refrigerator much or watch a movie on the computer,” says Rebekah, standing in the kitchen in stained cotton cut-offs and a faded T-shirt that shows up on Stephen that afternoon. The two, both slim and around 5’,7″, often share tops and even jeans. They have matching 10th-anniversary tattoos, an electrical symbol of a double diode, or lightning arrester. ”People in the solar industry call them lucky charms,” Rebekah explains. “It means that the two of us together are more capable to deal with trauma and stress than we are apart.”
She shows me their new appliance, an induction hot plate, around which a magnetic field is created to send an electrical current that heats only the pot and not the stove. “It’s my new favourite thing. It’s this crazy thing that works like a microwave?” she says, her voice occasionally rising in youthful upspeak. ”Unfortunately, we didn’t know about it until after we’d finished the book.” They also have a two-burner ethanol stove, and when the weather cools they use a wood-burning stove for heating and cooking.
Stephen, with a quick kiss and a “bye, sweetie” to his wife of 12 years, leaves on his bike to run some errands. “Be careful riding your bike in the rain,” she calls out, having earlier reported a band of showers moving in.
Rebekah takes me through the kitchen, where the Hrens are having their first non-energy-related home-remodeling job done. For that, they arranged a labour trade with carpenter friend and former housemate Kevin Svara. Today’s excitement is that Svara will complete the kitchen cabinet and countertop of wheat board and bamboo plywood. Luckily, the area’s first green-building store opened just around the corner from the Hrens. “Common Ground being here makes it a lot easier,” Rebekah says. “I think we’ve tried out almost everything they carry.”
The kitchen also houses a compact dishwasher. Much of a dishwasher’s power goes into heating water, so the most energy-efficient ones have the shortest cycles, as well as a cold-water option. “Stephen was weirdly convinced it couldn’t beat washing [by hand], but it does. It only uses three gallons of water,” says Rebekah. Stephen explains later that he had to think that one through. “I can have Luddite tendencies, but it does seem to be amazingly efficient.”
The most critical apparatus in the kitchen isn’t for cooking. On the wall near the back door is the power metre, which Rebekah watches somewhat obsessively. “The house is drawing negative 3 amps,” she declares, which means the house is using more power than it’s producing, a typical reading for a dark day.
The Hrens have a laundry list of energy-saving techniques and devices. They use a solar hot water heater and passive solar heating, which means allowing sunlight to come through windows (preferably facing true south in the northern hemisphere). This fall they’ll install a solar air heater, in which panels with air space are positioned south on the roof or the side of the house. When air from the house comes in contact with the panels, it’s warmed, and usually a fan is used to distribute the air throughout the house. In the kitchen, they collect greywater from their sink and front-loading washing machine in a 30-gallon tank outside to use for extra irrigation.
The house is decorated in grad-student style. Most of the furniture is donated, and the artwork ranges from an old pinball machine face to indigenous art from the couple’s travels to various countries including Mexico, Peru, India and Nepal. “India had a big influence on us,” Rebekah says. “That was the first time we realized how badly the environment was being destroyed, and how Americans are so rich.”
Their international travel days are pretty much in the past now because, while Rebekah still flies to teach solar installation courses, Stephen has stopped completely. They conducted a cross-country summer book tour by train, and they’ll travel by boat to a family Christmas vacation in Mexico. “Flying started to seem like an extension of driving, and they’re both totally unsustainable,” Stephen tells me later. “It’s impossible for planes to exist without fossil fuels. The other thing is the whole egalitarian aspect. Only 5 percent of the world population has ever flown.”
When Stephen returns from his errands, still dry, he gives me a tour of the exterior projects. They installed a metal roof because it facilitates rainwater collection and it’s also a natural radiant barrier, keeping the house cooler in the summer. They created a green roof, a catch-all term for any roof with vegetation on it, using pond liners and planters. That also helps to reduce their roof temperature, gives them an attractive patio space and even supplies cooking ingredients in the form of sage, thyme and rosemary.
But the most attention-getting transformation is the sprawling garden on the one-third-acre (some 1,000-square-metre) lot. The former lawn is a startlingly healthy and unruly mix of vegetables (many perennials), fruit trees, cooking herbs, medicinal herbs, berries and nuts. A horizontal shading trellis of muscadine vines snaking along the western side of the house partly covers peeling white paint. “A lot of people in the city don’t even think about doing this, but things grow really well here,” he says. “One day this jogger ran by and stopped in his tracks and said, ‘It never occurred to me you could have fruit trees in the city.’ And he knew everything about fruit trees.”
Much of the design, planting and tending of the garden is credited to their friends and tenants, Kyra Moore and Keith Shaljian, who rent the in-law apartment. The couple operates Bountiful Backyards, a company that provides edible landscaping, and lately Stephen’s part-time employer. Their apartment is set up to use some of the Hrens’ solar power.
Today Rebekah has to do a few hours of fieldwork to check on a solar installation job she did with her employer Honey Electric Solar. We take off in the Mercedes, which the Hrens converted to run on used fryer oil instead of diesel. A friend did the conversion using an Elsbett kit, a German invention that, by modifying the fuel injectors, allows the original fuel tank to be used with any combination of veggie oil, biodiesel and standard diesel. We arrive at a suburban house to check on the 2,800-watt photovoltaic system she and her partners had recently spent three days installing. “We like to come and turn it on ourselves, but it was a sunny weekend and the owner couldn’t wait,” she says.
Rebekah, who teaches photovoltaic installation through Solar Energy International, says women are a rarity in the business. “I talk to customers about the system on the phone and do the emailing, but when I go to the house to do the work, they’re usually surprised.”
While the Hrens have their individual jobs (Stephen also writes fiction), much of what they do is together. “They’ve definitely always worked as a team, or they could never have done all they’ve done,” says Kelly Dimock, who has been close to Rebekah since they were 13. She was there when Stephen courted Rebekah, when he was 17 and she was 16. While he eventually won her over, both sets of parents were wary, especially after the young lovers ran away in Stephen’s car a couple months before he was to graduate from high school and Rebekah was a junior.
“The plan was we would go to Mexico and live on the beach,” Stephen says. “We hated high school. It seemed so utterly stupid.” (Adds Rebekah: “We both had societal issues.”) “We thought 40-hour-a-week jobs were stupid, mortgages were stupid. We definitely wanted to avoid the career thing.” His mother reported them missing—the car was registered to her—and the police finally found them in Alabama. “By then the charm had worn off,” Stephen notes.
After Rebekah finished high school, they attended the University of Texas at Austin before transferring to Chapel Hill. His degree is in economics and hers is in political science. During and after college, they lived for two years in a yurt until it collapsed under snow.
When they said they next moved to New York City, I thought they were joking. “That was a tack left,” admits Stephen.
She worked in marketing at the accounting giant PricewaterhouseCoopers and he was an economist for the state real estate board. “We only made it a year and a half, but we saved like $40,000,” Rebekah says. “It was fun but stressful.” All along, they were more interested in being self-sufficient than in conserving resources.
That changed after the terrorist attacks on September 11, 2001, when the peak oil movement, which focuses on the point when the maximum rate of petroleum extraction will be reached, grabbed Stephen’s attention. “I realized, Wow, not only are resources limited, but there will be less and less available. It made everything seem like it was built on a house of cards,” he says. From there, Stephen started a meetup.com group called NC Powerdown, met a crowd of like-minded people, and launched the quest for a fossil-fuel-free existence. “It seemed like a clear road,” he says. “You were either going to withdraw or engage.”
The book they wrote is the Hrens way of engaging.
I ask Stephen if he thinks people tend to feel guilty around him and Rebekah. “I don’t know, probably,” he laughs. “But I try to not make them feel that way. You don’t want to be too preachy. That’s a fear with the book.”
In the evening, the couple work side by side in the kitchen chopping vegetables for a dish Stephen concocts in a pressure cooker. “It’s with rice but it cooks up like risotto,” he says. In the pot he adds fresh onions, peas, kale, garlic and parsley, either from their garden or the Durham farmers’ market. He stir-fries squash and onions for a side dish.
Before going to bed I show them the small fan I’d brought to block out the street noise below. “I’ll need to vet it,” Rebekah says, not impolitely. I’m amused watching her take a metre to my fan. While apparently it uses more energy than advertised, it passes inspection.
In the morning, Stephen and I head off to work with Bountiful Backyards after he sets out a pot of potatoes to cook all day in the homemade solar oven. The cooker, which looks like a box with a window, can reach 300 degrees Fahrenheit (150 Celsius) on a sunny day, hot enough to cook stews, roasts and even cookies.
“See that Bradford pear?” Stephen says when we arrive at the two-story house in a new development. “That tree will be dead in five years. It’s what every landscape person puts in.” By the end of a full day in the backyard, the crew has installed a rain barrel, planted a fig tree and some flowering plants and constructed two spiral-shaped herb gardens.
Stephen is thrilled to see more mainstream folks moving toward sustainable living, including his brother Philip. “Stephen started sending me emails about peak oil five years ago, and it all sounded too crazy,” says Philip Hren, a 48-year-old computer programmer who lives in nearby Cary. “Then I learned all the facts about oil and had an energy audit.” Since then, he’s added insulation and a metal roof to his family’s home, and purchased a solar hot water heater and a Prius, all changes for which he says he owes Stephen.
Rebekah’s childhood friend Dimock, who credits the Hrens with inspiration for her own environmental changes, thinks the couple has a way of getting people’s attention. “They’ve got a magnetic draw,” she says. “People meet them and think, ‘I don’t know anyone who’s done all these things and knows all these things.’ People like to be around people they learn from.”
Rebekah’s mother, Linda Wharton of Raleigh, says her daughter and son-in-law “always had a vision about what they were going to do, but in the beginning it wasn’t clear where they were headed. I’m just in awe of what they’ve done.”
When I ask the Hrens if they think the book could put them in demand as consultants and speakers, they concede it’s possible, but because they don’t fly it seems unlikely. “I think we have the responsibility to live the life we write about, doing what we said we were doing in the book,” Stephen says. “Instead of travelling all over the place, we want to be active in our community.”
Whatever the Hrens’ next project (one dream is to start a hybrid/alternative-fuel car-sharing co-operative), communicating their knowledge about it will remain a component. “You can do a lot yourself, but actually it’s really tiny,” Stephen says. “You’re not going to make any kind of difference unless you go out and educate people. It’s really about changing society.”
Rebekah and Stephen don’t expect their book to bring about wholesale change, but they do hope some readers will be moved to join them in what they feel is their “moral obligation to act.” In the quiet revolution that’s changing the way we produce and consume energy, their actions speak as loudly as their words.
The to-do list
It’s hard not to be inspired by the Hrens. Here are six simple projects from The Carbon-Free Home anyone can tackle:
Write an energy diary
For a week, month or year, make an inventory of your appliances, logging how much energy is used, including trips in the car. Increased consciousness about energy use brings down consumption an average of 15 percent.
Insulate the refrigerator
The Hrens estimate this takes about a weekend, requires moderate carpentry skills (uh-oh) and can reduce energy use by up to 50 percent.
Seal drafts
The Hrens guide readers through a do-it-yourself approach, or you could hire a pro to blow in wall insulation for you.
Insulate the hot-water tank and pipes
It will take a few hours, cost about $50 and save you a good 10 percent on water heating bills.
Seal windows
Add rope caulk to eliminate potential drafts. It can easily be put in place and later removed by hand, without using a caulking gun.
Grow your own food
Plant edible perennials and potatoes. Using a potato barrel, “even folks with no gardening experience can organically grow dozens of pounds of this extremely versatile vegetable with a minimal input of effort,” according to the Hrens’ book. Plant edible perennials, including vegetables, for a less maintenance-intensive garden. Care for some braised lovage and good King Henry for dinner, dear?
