Suburban builder constructs 'one-watt' house

Ultra energy-efficient homes, known as certified Passive Houses, are few and far between in the United States. But a house in far West suburban La Fox, near Geneva, will soon receive that designation.

The design in based on building practices in many European countries, most notably Germany and Austria, where Passive Houses are common and will soon become the standard.

Passive Houses feature fully enclosed, super-insulated envelopes (walls, windows, roof and foundation) with insulation values of R40 to R70 in this climate; a low-load fine-tuned heat source, other than a furnace; and a supply of fresh air from a highly energy efficient heat recovery ventilator.

A certified Passive House of 2,000 square feet requires no more electricity to heat it on the coldest day of the year than the electricity required to run a hair dryer (one watt per square foot).

Marko Spiegel, president of Conservation Technology International Inc., based in La Fox, is responsible for bringing the Passive House concept or One-Watt House to the Chicago area. And now, like Frank Lloyd Wright once did in Oak Park, Spiegel has chosen to showcase his work on his own home, using it as a laboratory of sorts.

A mechanical engineer who once ran the antenna group for Molex in Lisle, Spiegel became inspired to tackle advanced residential building technologies while driving home from Florida in early 2005. After passing scores of messy building sites in Georgia, it occurred to him that “here is an immature industry that is in need of some major innovation.”

So he compulsively researched ideas and stumbled upon the Passive House concept. The more he looked at it, the more sense it made to him. It is a predictable, measured approach that ensures the optimum level of energy efficiency with great improvements to thermal comfort and indoor air quality. He could see great potential for a reduction of energy demand when Passive House concepts were applied to buildings. The fact that such improvements could be measured and proven and that the approach has such positive long-term environmental consequences appealed to Spiegel.

So he left Molex and began CTI in October, 2005.

“It is funny how circles tend to close themselves in funny ways,” Spiegel said. “I grew up in East Germany. I wanted to become an architect but there were only a few openings in the country and I became a mechanical engineer instead.”

He has always felt connected to buildings, however, seeing them as long-lasting entities that need to be built correctly. They are not a disposable commodity to him. So when he began researching building technologies and found that the most advanced methods had come from his home country, he was not really surprised.

“Subconsciously, I always knew that Germany was known for its construction technology, just like the United States is known for its military and communications technology. So the fact that the Germans and Austrians developed this advanced building method didn't really surprise me much,” Spiegel said.

This is the sixth highly energy-efficient house on which CTI has worked, he said. The other five homes given energy upgrades are located in Wayne, Oak Park, Batavia, Oregon, Ill., and Bloomington, Ind.

The Spiegel home was built in 1989 and was considered energy efficient for the time. Spiegel and his wife, Cynthia, purchased it in 1997 and put on an addition in 2003. It is 3,880 square feet and sits on 1.3 acres.

Even though he had been employing the Passive House concepts in his business, Spiegel had only implemented minor improvements to his house.

“When our leaky-21-year-old windows and siding needed to be replaced, we decided to use the opportunity to thoroughly update our house,” Spiegel said. “We also had to deal with other challenges adding to the need for change: catching 65 mice in 2009; our daughter waking up with snowflakes on her face because her window would not latch shut anymore; no natural light in the basement; and thermal discomfort, especially in the wings of the house.”

Spiegel wanted his family to enjoy the warmth and comfort, as well as the indoor air quality, others were enjoying thanks to his 5-year-old company.

So he began doing the calculations and determined he could indeed transform his family's home into a certified Passive House that would be 85 percent more efficient that the average home and would set an example of energy demand reduction in suburban homes.

“Renovation opportunities only come along a few times during the life of a building,” Spiegel said. Putting more thought into improving many qualities at once will help ensure that a home's value increases and that it uses fewer natural resources.

“I am passionate about the environment,” Spiegel said, “but you don't make these changes to a house just for the energy performance. It is because of the improved quality of life. These houses simply feel great. So I hope that in 10 years, having one of these houses will be a bit of a status symbol because, after all, you spend most of your time in your house.”

So this summer the La Fox home of the Spiegel family became a beehive of activity as the family undertook a $200,000 improvement project. Because the windows, siding, roof and gutters needed to be replaced anyway, the only relevant Passive House cost is the incremental upgrade from regular windows and the addition of insulation under the new facade, in the roof and around the foundation, Spiegel said. All in all, the Passive House work cost $125,000.

Digging an outdoor entrance to the basement, complete with large windows to allow natural light into the lower level did not directly contribute to energy efficiency. But this was an opportune time to make the change. The same goes for the new patio, breezeway and painting of the garage.

They dug a trench next to the foundation, all the way around the house. They then removed the old drain tiles and replaced them; resealed the foundation to protect against moisture; and then added six inches of extruded polystyrene insulation to the outside of the foundation to protect against rodents and cold; and then covered it with mesh and stucco to adhere it to the home. They also added aluminum flashing on top of the foundation to protect against water and temperature fluctuations.

The crews also installed a small pipe in the bottom of the trench, all around the house. It is a closed system filled with antifreeze and connected to a small pump that it circulates around the house below the frost line, to extract heat from the ground. It is attached to a heat exchanger that preheats incoming fresh air in the winter.

The system can also help cool incoming air and dehumidify the home in the summer, although a small air conditioner is still necessary, Spiegel found.

They also added extra insulation in the joists above the basement to create a thermal barrier between the basement and the first floor to further strengthen the home's envelope.

On the outside of the aboveground walls, the crews removed the old siding, added six to eight inches of foam insulation and then covered it with stucco. And all of the home's windows were replaced with triple-pane wood windows with insulated frames from Germany. The Unilux windows, provided locally through Gilkey Windows, have a U-value of 0.12, which Spiegel said is incredible.

“They are more expensive than American-made wood windows, but they will survive me because they have a life of 50-plus years. So considering their long life, they are cheaper than American windows, which generally only last 20 years,” Spiegel said. “Germans wouldn't accept having to throw out windows after only 20 years, so they construct them to last.”

Finally, they addressed the roof.

“We cut off the old overhangs and framed a new roof structure that involved doubling the overhangs. When you do that it lengthens a building's life because bigger overhangs better protect a home's walls and windows. There is also some improvement in summer cooling costs because of improved shading of the house,” Spiegel said.

The insulation level on the roof was also improved from R-35 to R-70 by keeping the original roof sheeting, adding a thick layer of insulation and then installing a second layer of sheeting before putting on the shingles.

“When you thicken the roof and walls it takes come creative thinking structurally to make it work,” Spiegel said. “You need much longer screws, etc. But if we ever suffer a tornado here, our roof with be the only one still left standing.”

The installation of a 93-percent efficient heat recovery ventilator will be the last step before finalizing Passive House certification with a blower door test conducted by an independent third party.

But the Spiegel family is feeling the improved interior environment already. Even on these cold December days, the home has been extremely comfortable and their November gas bill showed a 66 percent drop in therms used per day compared to last November, even though all of the improvement work has not yet been completed.

“We are thrilled with the unusual thermal comfort and wonderful indoor air quality of our home. The colder it is outside, the more the qualities of this passive house are felt,” Spiegel said.

“The thing I enjoy is that our home not only performs well, but it looks nice and has a simple, timeless quality to it that will never become outdated,” he said. So while Passive Houses are state-of-the-art in terms of technology, nothing makes them look unusual or futuristic or out of place in their neighborhoods and environment. Everything that distinguishes them from other homes is hidden from view.

For information, contact CTI at (630) 262-1195 or go online at

  Spiegel explains some of the features that make his home more energy efficient, including thick, insulated exterior walls and roof. Rick West/
  SpiegelÂ’s energy-saving Passive House can be heated in the winter for about the same amount it costs to run an electric hair dryer. Rick West/
  Wooden triple-paned windows made in Germany were installed throughout the Spiegel home. Rick West/
CTI rebuilt the roof to add another layer of insulation and extend the overhang. Courtesy of CTI
A trench was dug around the Spiegel home to insulate the foundation. The family also added a walkout basement door and windows to bring in natural light. Courtesy of CTI
A thick layer of foam insulation was added to the exterior walls, which were then covered in stucco. Courtesy of CTI
Before the project began, Spiegel knew he needed new windows and siding. Courtesy of CTI
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