Associated Articles
Leave your carbon footprint at the door
A North Carolina couple aims for a 'carbon free' home and offers a do-it-yourselfer's guide to cutting household fossil-fuel consumption
CRAIG SAUNDERS
From Friday's Globe and Mail
August 15, 2008 at 12:00 AM EDT
The 1930s house Stephen and Rebekah Hren renovated for themselves in Durham, N.C., is a hard-core environmentalist's dream: It is carbon-free.
That is, the systems in it consume no fossil fuels and do not emit greenhouse gases. The changes the couple made to their home and lifestyle are documented in their new book, The Carbon-Free Home: 36 Remodeling Projects to Kick the Fossil Fuel Habit (Chelsea Green Publishing), a do-it-yourselfer's guide to cutting fossil-fuel consumption in the home.
Drawing on their experiences, the Hrens offer an accessible guide to dozens of projects, from simple to complex. Some are straightforward, such as insulating the hot water tank, while others require more work and, for most people, a bit of motivation — such as building a "biogas digester" to convert human waste into cooking gas. Not every project is for everyone, and even the Hrens haven't started making their own cooking gas, yet.
Most "green" homes going up today have better insulation and more efficient heating systems than older, conventional homes. The Hrens go a few steps further to cut out fossil fuels altogether.
They have a solar hot-water panel and a 1.2-kilowatt solar array on the roof to supply their hot water and electricity, and use a solar oven for baking and cook on an alcohol stove.
Their metal roof keeps the attic cooler than asphalt shingles. In summer, they use fans instead of air conditioning, and a vine trellis shades the sunny side of the house. In winter, they exchange the screens in their porch for corrugated plastic to capture more heat from the sun, and are putting in a solar heater. After all, even in balmy North Carolina, it gets chilly on winter nights.
Through a combination of changes to the house and their lifestyle, their home contributes virtually nothing to climate change.
While the Hrens' approach may seem extreme in some ways, their attitude about going green at home is pragmatic. They began by keeping an "energy diary" to figure out where they used electricity, oil and gas in their home. Then they began working to eliminate any excess energy use, unplugging appliances to cut the power used while on standby, for example.
"Do what you can when you have the time and money for it," says Mr. Hren, a 34-year-old restoration carpenter. "Anything that's not supporting the status quo is a step in the right direction."
Their book suggests that homeowners start with easy energy-saving changes, and leave the expensive ones, such as installing solar panels, for later. Which is ironic, considering that Ms. Hren, 33, makes her living designing and installing solar systems.
Their three-bedroom, two-bathroom Durham house was their second carbon-free house. It was while working on their first home project that she first became interested in solar power. Their first idea was to build an environmentalist's dream home in the country. In 1996, they bought a lot 10 kilometres from Roxboro, N.C., and built a cob house. (Cob is a mixture of straw and clay that makes thick, sturdy walls.)
Ms. Hren, a licensed electrician, was keen on solar power so she read a lot, assembled the necessary parts and built her own system for the cob house for less than $6,000 (U.S.). "We're very budget-conscious, and I was like, 'I can do it for less than $10,000.'"
But by the time they finished that house, they realized that by commuting nearly 50 kilometres to their jobs in Durham, they were doing more environmental harm than if they lived in a conventional house in the city.
So they rented out the cob house, bought their aging downtown digs in 2006 and got to work. So far, they have spent about $30,000 on the renovation, including about $10,000 for the 1.2-kilowatt solar power system, which provides all electricity for the house as well as a solar hot-water panel. Solar hot water systems are much more efficient than photovoltaic systems, making the solar hot-water heater one of the biggest savings in the house.
The Hrens, who do not have children, also figure they each put about a year's worth of labour into the house.
Ms. Hren says their most effective tool was their energy diary. They researched the consumption levels of all their appliances, large and small, and kept a log of how long they used each one. Then they could see where most of the energy was going, and work out which lifestyle changes they could make to reduce their overall carbon footprint.
The couple saw the biggest energy savings from the most dramatic changes. Blowing fibreglass insulation into the walls and attic cut their heating and cooling costs by an estimated 40 to 50 per cent. The house had an ancient boiler and rusted-out radiators (the previous owner told them it cost more than $500 a month to heat the house in winter).
They also upgraded the windows and installed insulated curtains.
"They cost money, but they're a good investment," Mr. Hren says of such expenses. "You're saving money over the long haul and reducing carbon-dioxide emissions."
The Hrens open their window blinds in the daytime to take advantage of the sun's heat. They use a woodstove for cooking and for heating on cloudy days, though they plan to install a solar air heater, essentially a box that mounts on the exterior of a house (preferably on a south-facing wall). Small fans pull cool air from the house into the bottom of the box; the sun warms the air, which rises and is blown back into the house.
Mr. Hren says their monthly household bills now total $40 for water and sewage, $15 for cooking fuel and, in future, about $150 for a cord of wood (so far, they've been using wood from an old oak tree they removed to improve the home's exposure to the sun).
The Hrens' other energy-saving moves cost little to nothing, though there's no question some would be challenging for families with babies and toddlers (think loads of diapers) or teenagers immersed in the Internet and Wii games.
Hanging clothes to dry was a key move for the Hrens, given that using a clothes dryer for an hour a day consumes about as much electricity as their $10,000 solar-power system produces.
Turning down the hot-water heater to 48 degrees from the factory preset of 60 degrees resulted in energy savings of 15 to 20 per cent, Mr. Hren says. And they unplug standby appliances and battery chargers when not in use; a television on standby uses more energy than watching it for two hours a day, he notes.
When it comes to solar-power systems, Ms. Hren says there are a couple of reasons to leave photovoltaic panels until last, because a number of changes must be made before installing them.
For example, the Hrens chose a metal roof because it's easier to collect rainwater from metal; asphalt shingles shed a lot and don't drain as easily. Municipal water systems use a lot of electricity, so capturing rainwater to wash clothes and water the garden indirectly cuts carbon emissions.
Most importantly, solar-power systems are expensive. Before looking at solar electricity, the couple recommends considering a solar hot-water heater, which is much less expensive. The one in their home normally costs $7,000, but government tax credits brought it down to about $3,000.
Many Canadian cities, including Toronto, also offer subsidies and financing that make solar water heating an attractive option.
Special to The Globe and Mail
Print this page.
