Building the NewenHouse Kit Home: Living in a Passive House

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Sonya Newenhouse, Ph.D. is an eco-entrepreneur who enjoys providing practical and creative solutions to help individuals and organizations live and manage green. Her firm, Madison Environmental Group, provides LEED green building and sustainability consulting services. She is also founder and president of Community Car, a car sharing organization in Madison Wisconsin. Currently she is developing NewenHouse, a business that will provide super-insulated sustainable kit homes.

I’m here to report what it’s like to live in a Passive House in winter in Wisconsin. Some blog readers have emailed me and wondered how the house is performing. I’m very pleased to report that living in a certified Passive House in Wisconsin in the winter is working. In fact, it’s working better than we expected. Since the New Year we have relied solely on the heat from the sun and the heat created from our daily home activities. We have yet to turn on any supplemental heat (our two Eco-heater 400-watt wall units nor our 250-watt bathroom ceiling heaters). The lowest the house temperature dropped was 55 degrees Fahrenheit. My husband Cecil and roommate Bjorn have been good sports in joining me to test the house. You know they are committed to the project when you ask, “Let’s see how cold it gets without turning the heat on,” and they agree to the experiment. Every day when we come downstairs for breakfast around 7 a.m., we check the indoor and outdoor temperatures. If I’m home in the middle of the day, I record the indoor temperature. When we go to bed (around 10 p.m.), we check both the indoor and outdoor temperatures again. 

We also keep track of the sun and record if it’s sunny or cloudy. We record when we turn on the back-up electric water heater, which we do only if the water temperature from the sun drops below 105 degrees Farenheit. Otherwise we leave the breaker to the water heater off.

Velux 80-gallon insulated solar hot water heater with electric backup. Photo By Sonya Newenhouse.

Following are performance measures of the house for 30 consecutive winter days in Wisconsin, 27 of which were below 32 degrees Fahrenheit (below 0 degrees Celsius). When it’s sunny out, the temperate inside during the day is pretty steady around 74 degrees F (23 degrees C). There were 12 days where the indoor temperature was above 64 degrees F (18 degrees C) when we woke up. The lowest it ever dropped to in the house was 55 degrees F (13 degrees C ). We only had three days where the indoor temperature reached below 60 degrees F (16 degrees C) when we went to bed, and overnight the average temperature drop was only 3 degrees F. The greatest drop over night was 6 degrees F. The large triple-pane fiberglass Inline windows from Canada work great and lose little nighttime heat. Out of the 18 days when we recorded the mid day temperature, there were 14 days when the house warmed to above 68 degrees F (19 degrees C).  

A reminder–we intended to use our heaters to stay above 68 degrees F (20 degrees C) every day, but we wanted to test the house and see how it performs if we don’t turn the heat on. The total heat output of our four small electric radiant heaters is similar to the amount one hair dryer generates. So it’s clear that one hair dryer in fact can keep this house toasty warm. Remarkable. Thank you to Carly Coulson and the Passive House experts in the U.S. and Europe who have worked hard to improve building standards to achieve such deep energy-efficiency results.   

I’ve become a sun worshiper. I have never before been so in tune with the number of hours the sun shines, but you can feel it right away in our house. The past 30 days the sun came out 16 days. If it’s cloudy more than two days in a row, the house cools down a bit and you need to put on a sweater. The concrete slab is also working remarkably well. The 12 inches of foam insulation under the slab keep it comfortable. It’s not warm, but usually it’s not cool enough to need slippers in our shoes off home. The outdoor temperature does not predict if it will be warm or cold in the house; the only steady indicator is the sun. On sunny days, heat stores up in the house. For example January 19th was a sunny day, and the next day when we woke up it was 63 degrees F (17 degrees C)  inside, and -8 degrees F (-22 degrees C) outside!  During the night the indoor temperature had only dropped 5 degrees. The sun often shines when it’s very cold in Wisconsin. 

Twice Cecil and I woke up with raspy throats and thought we may need to figure out how to add humidity to the house. Both times I discovered that the HRV (Heat Recovery Ventilation Unit) was on the highest setting (the 3 setting) by accident. It’s meant to be at the mid range setting, 2. The HRV is so quiet that you hardly notice when it’s on high. Our HRV control panel is in the kitchen behind our hanging cast iron frying pans, so I think the pans bumped it. In the next home, we will move the control away from obstructions. 

We check this thermometer every morning and night, and this HRV control panel was bumped by our pans. Photo By Sonya Newenhouse.

This winter we’ve enjoyed hosting tours, dinner parties and overnight guests. Last week we hosted an Organic Valley Board Member, Steve Pierson, who lives 30 miles south of Portland, Oregon, and served him homemade pizza. Here’s a bit about Steve and his wife Susan’s farm. Bjorn gave us the pizza recipe, and it’s now a weekly dinner choice. A couple of Fridays ago we hosted a small tour of the house for new clients of Whole Trees Architecture. Two of the guests, Denise and her daughter Della have blogs I thought I’d share with you: Digging in the Driftless and As If People Matter. Both mother and daughter are very dedicated to natural building techniques and hopefully they’ll visit again soon. One of our guests over the holidays, Ian Klepetar found us via, a website for traveling cyclists. He showed up at our doorstep on December 22, stayed with us a couple of days, helped us get ready for our holiday party, and rode his bicycle to Madison on Christmas Eve (100 miles). He started the Bicycle Benefits program with some friends and now has a community minded idea called the Muffin Exchange. Read here to learn more and be inspired.

Ian Klepetar finds our house via for traveling cyclists on December 22. Photo By Sonya Newenhouse.

We will continue to host NewenHouse OpenHouses once a month in 2012. Usually they are the fourth Friday of the month, but sometimes the date may change, so check with us before you attend. The next 3 OpenHouse dates are: Fridays February 24, March 23, and April 27. Email or call me with questions at or (608) 220-8029.  Our Address is 422 Hickory Street, Viroqua, WI 54665.