According to architect Mark Siddall, the Passivhaus Challenge – to see how long people who live in Passivhaus (also known as Passive House) or EnerPhit (the standard for renovations) could go without turning on their heat – was a spur of the moment idea. He tells Treehugger:
He then decided to put it up on Twitter. "As I saw it this little experiment was taking place anyway, I had no expectations that other people would actually join in."
Siddall set up the format, asking for the temperature in Celsius and also a request: "feel free to add a little about how you feel that would give a little insight into your personal experience." Then day by day, interest grew, it became a phenomenon; people with certified Passive House buildings, and near Passive House, all over the world. Mark asked for the temperatures in Celsius but the Treehugger standard is to use Fahrenheit, so I whipped up a conversion table:
The challenge is only halfway through, but I am showing a few of the most recent entries, except for this one from George Mikurcik's Old Holloway Passive House; it's my favorite these days, and once again he's got the dog in the photo. You can see the dog inside the house here.
We asked last winter how the house was holding up and were told that the careful placement of windows made a difference; there was no Passivhaus Challenge last year but they still rarely used the heat.
Here's the latest from Old Holloway; cooking a roast seems to help.
The only house in this challenge that I have actually visited is Ben Adam-Smith's (seen on Treehugger here) and I am pleased to see that it is holding up to the challenge.
The Shepherd's Barn renovation is also holding up. Renovations have a slightly more relaxed standard for air infiltration and energy consumption, so one might expect it to not do as well, but it is still, after two and a half days, a sort of comfy (by English standards) 64 F, but I bet that the heat comes on soon.
Andrew Michler's (seen on Treehugger here) house is in Colorado, and it is cold there in either Fahrenheit or Celsius. Alas, the water line from his cistern is not built to Passiv House standards and froze up.
John Semelhack is in Charlottesville, Virginia, and says "FYI - we're not a Passive House (we're close)...just playing along." It's pretty cold there, and his house dropped about 6 C in 54 hours; that's pretty good, but that is still significantly more than we are seeing in the certified Passive House buildings, I think a good demonstration of why one should really try to go for the true Passive House numbers.
Engineer Martin Gillie's house is probably like my own; in not very much time, the inside is just about the same as the outside, and you have to dress for winter. As he notes, "You lot may have a point...!"
John Butler is a certified Passive House consultant, but he doesn't live in one. Like me, he wishes he did. Because we all learned something from this.
It was such an interesting coincidence that this challenge started just after the worst of the cold weather in Texas, where people have suffered so much. Everyone participating in the Passivhaus Challenge has the option of turning on the heat, or even cooking a roast, but the challenge clearly demonstrates that the Passive House approach makes a real difference in resilience. Everyone here was having a bit of fun; as Mark Siddall tells Treehugger:
The real lesson here is that every home should be built this way. No doubt some people would complain that it is too expensive, but one only has to read the news to see what the costs are when you don't.