Sustainable Houses

Homeowner Turns 1910 Farmhouse into the First Passive House in Idaho

Vic Webber, a former Navy pilot turned passive house design consultant, is working hard to turn his family’s 1910 farmhouse into the first passive house in the state of Idaho.

From the outside, Vic Webber’s house in Fairfield, Idaho looks like any other farmhouse in the area, but on the inside it’s undergoing a serious makeover that will result in a 90% less energy consumed for heating and cooling. Unlike the Leadership in Energy and Environmental Design (LEED) which awards points according to a series of factors including sustainable materials and renewable energy, the Passive House standard focuses on energy conservation. A passive-house certified home focuses on reducing energy consumption without the use of expensive solar-generated electricity. “We’re not allowed to use photovoltaics to meet our standard,” Weber said. “We focus on conservation, not on being able to generate our own energy.” This is achieved by making the house air-tight and using super-efficient insulation.

The Idaho passive house design consultant stripped his house down to the 2×6 studs, filled the gaps with super-dense insulation and added an extra 6-inch of rigid foam insulation. Including the siding, the walls of this old farmhouse are now 14 inches thick, almost twice as thick as the outside walls of a traditional house. Webber claims the insulation prevents thermal bridges. “A typical stud wall, it’s basically a heat bridge to the outside. We eliminate any easy access for heat to leave the house.” One of the priciest elements used in the drastic transformation of the house were the super expensive krypton gas-filled windows. “If I wasn’t doing a passive housing project, I wouldn’t have used the windows I did,” he said. But “the climate was such that we needed these windows to make this work.”

One of the problems Webber found himself confronted with while working on his passive house was air circulation. A traditional house has natural ventilation, as the air circulates through crawl spaces around doors, windows and other cracks, but that’s just unacceptable when talking about a passive house. Instead, Webber says the air in his 2,500-square-meter home is completely pumped out and every three hours. Fresh air is heated through various methods like a ground-based heat exchange system where the natural heat of the ground slightly warms intake air, or another where the exhaust air helps to boost the temperature of the intake air. This eliminates the central furnace and makes the air fresher than that in a conventional home. “In a passive house, you have a constant stream of fresh air coming in. The air quality is unmatchable.”

To achieve his goal of reducing energy consumption by 90%, Vic Webber had to use techniques that aren’t exclusive to passive houses like solar-powered radiant heating in some rooms and a solar hot-water heater , but he hopes these will cause energy costs to drop by 70%. But all these improvements do come at a cost, and although he says the costs of renovating his farmhouse were hard to estimate because the process was so thorough, Webber estimates aiming for the passive house standard increased the cost of the remodel by 10% – 15%.

Believe it or not, there are less than two dozen passive houses in the whole of the United States, and when completed Vic Webber’s  will be the first in Idaho. He plans to hold open house tours that will hopefully inspire people in the region to embrace the passive house standard when they learn just how much energy they can actually save. “The goal of the project is to be a prototype for the area. In the end game, I’ll have a showcase house for people all over Idaho to see,” Webber said.

via Idaho Mountain Express

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