|A Home Without heat
This little house on the camas prairie is the blueprint for a form of building that may take us beyond fossil fuels
by Katherine Wutz
photos by David N. Seelig
From the front, the 1910 farmhouse looks like any other home in the tiny township of Soldier, 60 miles south of Sun Valley. The classic lines and old-fashioned front porch echo the early 20th century, an impression only slightly marred by the pink house-wrap across the front.
From the back, however, it's clear this house is different from its neighbors. A slate of solar panels turn their black faces south toward the Camas Prairie and sunshine, and a wall of floor-to-ceiling windows welcome the warming power of the sun into the farmhouse.
Once inside, the differences become amazing. Radiant heat, delivered through solar thermal panels, and sun streaming through the windows are the only elements heating the home. In a town where winter lows average 6 degrees, this house has no boiler. In fact, it has no standard-issue heating or cooling system at all.
Vic Weber, owner and constructive mind behind the renovations, designed the house around the burgeoning concept of passive house—in which there is no active heating or cooling, and what heat is generated is done so with über-efficiency. This little farmhouse on the Camas Prairie is essentially airtight. European-made windows and 12 inches of super-dense insulation combine to prevent cold air from coming in and warm air from leaking out. "It's not hard," Weber said. "Nothing we did [in building this house] is cosmic."
Weber and his builder, Kipp Thomas of Fairfield-based Eco-Construction, renovated the house according to the standards of the Passive House Institute, the American equivalent of the Passivhaus Institut, which started in Germany in 1996. The concept made its way overseas in the early part of the new millennium, but was slow to catch on. As of August 2010, 13 PHI-certified passive houses were recorded in the U.S., compared to 25,000 certified Passivhaus buildings in Europe, but several dozen more are currently under construction here.
According to the institute, passive houses are well-insulated, virtually airtight buildings heated primarily by passive solar gain—such as through Weber's south-facing windows—and partly through ambient heat given off by humans and electronic equipment. Any other required heat is provided by a small source, in this case Weber's solar panels.
Kevin Dugan, who designs and builds renewable energy systems with his company, Fairfield-based Western Energy, said Weber's home is so efficient at holding in heat that the main problem is trying to keep the house from getting too warm. On a slightly cloudy January day, the south-facing rooms were a balmy 70 degrees.
The airtight nature of the farmhouse does pose a challenge. Where a conventional house has natural ventilation—air comes in through gaps in crawl spaces, around windows and outside doors—in Weber's home this type of leakage doesn't occur. Instead, the air in the 2,500-square-foot home is completely pumped out and renewed every three hours through a ventilation system. This system uses a highly efficient heat exchange core to extract up to 93 percent of the heat from the exhaust air and siphon it back to the incoming air. The resulting fresh air then requires very little additional heat to boost it to room temperature. Additionally, incoming fresh air is pre-heated or cooled (depending on the season) via an earth tube system that uses the constant temperature of the ground to heat or cool incoming air. "The controlled, mechanical ventilation of the house, as opposed to the random, natural ventilation of a typical home, results in superior indoor air quality and comfort," Weber said.
The overall goal of building a passive house is to reduce energy consumption for heating and cooling by 90 percent. The idea of extremely low utility bills appeals to Weber, but his main motivation is his awareness that fossil fuel use is a growing concern that is only getting bigger.
Weber is so passionate about passive house because he's concerned his daughters—ages 5 and 7—will live in a world where fossil fuel use is no longer an option. "I know they're going to have problems with energy that we never had to think about," he said. "We need to start sipping from fossil fuels, not slurping. Let's make it last."
According to Dugan, passive-house building could become the way of the future, if only because of the obvious financial benefits. "No one likes paying a power bill," he said. "Everyone has some trepidation even opening their bills in the winter. So what can we do? Start building to passive-house standards."
The fact that Weber has managed to heat a three-bedroom home using less energy than a 75-watt light bulb, should prompt a revolution in green building. However, he estimates that building to passive energy standards increased the remodel costs by 10 to 15 percent, mostly due to more expensive windows and denser insulation. This poses an obstacle for uptake rapid enough to make a real difference.
The biggest challenge is builder objection. "It's fear of the unknown as well as fear of the unknown costs," Weber said. "They know how much it costs to build something a certain way," Dugan said. When Blaine County developed and approved its new energy-efficiency code in February 2011, many builders objected to the change based on the fact that clients would not want to pay the premium for more efficient heating and cooling systems, tighter windows or denser insulation.
Weber did pay extra for such items. "On the other hand, I would have had to put in a huge furnace," he said. "I had some big bills up front, but I'd have big bills regardless."
Dugan contends that most builder resistance to energy efficiency stems from fear of change. "But we have limited resources—we need to understand that. If we don't, we'll be digging up a 3-inch gas line to put a 6-inch one in. It's much cheaper to build to these codes than to put another power line in the valley."
Building to passive-house or energy-efficient standards protects power companies as well as homeowners, said Dugan. Power companies currently build what are known as "peaker plants," expensive backup plants that eliminate brownouts and blackouts during times of high power demand—such as a 110 degree day when all of Boise is running air conditioners. More efficient homes, especially passive houses, could eliminate the need for those plants. "Power companies have to spend a lot of money to build those plants only for peak loads," he said. "A more stable demand curve is much more in line with what the power company wants. They'd rather have a steady demand than to have to deal with those peaks."
Brian Poster, owner of Poster Construction in Ketchum, said his staff builds to the National Green Building Standard, but getting clients to build passive homes might be more complicated. "I build custom homes, and houses here are oriented toward views," he said. "If you're out Warm Springs [northwest of Ketchum], you're going to orient your windows to stare at the mountain, not to the south for passive solar."
However, Environmental Resource Center director Tom Wirth said minimizing energy use is the future of green building. "You can see it in the standards for appliances we use, like Energy Star," he said. "Those are constantly being pushed and improved."
Weber said he is working with Blaine and Camas counties to develop a "reach code" to encourage more builders and architects to adopt some of the energy-reduction standards he used in his house. Wirth has also seen building professionals take an interest in the concepts recently.
"It's something that architects seem to be pushing and learning more about," he said. But environmentally conscious people need to shoulder the burden of advocacy before it really catches on. "It's up to us to make this popular.";
For more information on passive house building and to find a certified passive house consultant visit www.phaus.org.
Vic Weber, a former U.S. Navy pilot, is the mastermind behind Idaho's first Passive House.
A wall of windows combines with a row of solar panels to suck up the sun's warmth and provide all the heat and hot water that the home needs.
Behind the scenes with the solar hot water system, which provides hot water on demand as well as radiant heat to the living room floors. Solar thermal panels heat the water, which is then cooled from the average 155 degrees as it passes through these tanks.
The warmest spot in the house.
in the south-facing room reads 70 degrees on
a chilly January day.
Weber splurged on these windows which are triple-paned and filled with krypton gas. More common in Europe, the windows swing open
in two directions for optimal ventilation.