The Hawkman Tours a Passive House, and Wants One for the EcoVillage

Post and photos by the Hawthorne Hawkman

About a year and a half, maybe two years ago, a group called the MinneAppleSeed Coalition approached the Hawthorne neighborhood with a desire to build a passive solar house in the EcoVillage. The Hawthorne Neighborhood Council lent its support to the proposal, and everyone was thrilled about yet another kind of groundbreaking activity that would happen in our community.

Well, as it turned out, we had to focus on getting rid of crime first, and many MinneAppleSeed partners had another opportunity to build a similar house before ours. This house, in Hudson, WI, goes even beyond passive; it will produce as much as three times the amount of energy it consumes. I wouldn't even call it a passive house so much as a passive-aggressive house, which is one reason they'll sell well in Minnesota.

For extensive coverage, this house, its builder, and those involved in its creation have their own blog at www.passivehouseinthewoods.com. But you can read more about my experience and how this relates to NoMi after the jump...

...The first pictures above are of course the house in its current state and some renderings of what it will look like once it's complete. It's kind of boxy and minimalist, but that's what the owner wanted. He's looking to emphasize the energy efficiency aspects and prefers low maintenance over a flashy structure.

Although there will be sources of solar power,



Much of the energy performance of this house is tied to the building envelope:




The building's walls are twenty-two inches thick, and made of layers of concrete and styrofoam. The initial reaction some people have is that styrofoam isn't very green. However, the standards used in this case don't deal so much with something being biodegradable. Instead, the focus is on the life cycle of the product; how much energy is negated by its implementation vs. how much energy is used in its production. In that regard, the building envelope is perhaps the highest-performing structure in the world.

It's also worth pointing out that the owner and builders are being very intentional about minimizing the building's effect on the surrounding landscape. Most new construction - especially projects in the exurbs - approaches landscaping by bulldozing over everything, then putting the house in, then creating the landscape the owner wants. But as one architect said, "Nature has a way of trying to get its area back." So this team is doing everything they can to build around the existing landscape.

Below, you can see what looks like a roof outcropping. However, that is merely how far out the wall will extend. Everything will be squared off once the envelope is complete.



What you see below with the pipes are actually areas where electrical sensors will be placed on the exterior. Along with a system on the roof, they will monitor when and how sunlight, wind, and other weather is affecting the house. Blinds will be automatically opened or closed depending on whether more or less sunlight is needed, and each window will have a manual override. There's even an iPhone app that can be used to monitor the energy performance of the house.

Nobody said anything about an orbiting satellite that can shoot lasers to instantly fry any potential home invaders, in-laws, or Sierra Club canvassers, but I think we're approaching that kind of technology here.



And here's what those windows will look like. There's a whole lot of technical reasons for why they're so thick and insulated, but what it boils down to is that the house is designed to utilize retention of energy (such as the sun coming through windows) rather than absorption/production (i.e. solar panels).



The doors are similarly insulated:




The ventilation system was also something rather novel. Instead of traditional ductwork, we have these series of corrugated pipes. These pipes have some kind of membrane that, through ventilation, transfers up to 82% of the home's energy back into itself during the winter. I'd really recommend you check out the house's official blog for a better explanation, because the best I can come up with is that the furnace is powered by dilithium crystals and anti-matter. Did I mention that the filters for the ventilation system are dishwasher-friendly? Well, they are.




The environmental features aren't the only extraordinary thing about this home, however. Just check out the amazing view:



In all fairness, it doesn't look like this all the time. Here's a more accurate representation:

Ho hum.

This house, and the technologies and philosophies behind it are truly groundbreaking. They both operate under the principle that the cheapest energy (kilowatt hour) is the one you do not use. With that as a foundation, the builders claim that even during the coldest days of winter, the worst-case scenario for heating a 1900-square-foot home will be equal to running two hair dryers at the same time.

Of course, the bigger challenge comes when we try to replicate homes like this in Minneapolis and elsewhere. Obviously we'll have cost to deal with, but let's not forget building codes. Several Minneapolis city inspectors and employees toured the house on a separate date and it's no surprise that they all had questions about how such a home would meet code here. And I have a tough time imagining a conversation where, during the final walk-through, the city inspector is satisfied with, "Don't worry, the heating system works exactly as needed. When it gets cold, I'll just turn on these two hair dryers here and the whole family will be warm and toasty."

While somewhat flippant, that comment isn't meant as a criticism of our inspectors either. They have a responsibility to uphold code and make sure homes in Minneapolis operate at a certain standard. But from the looks of it, green technology is developing at a much faster pace than our building codes may recognize. We'll have to cross that bridge when we bring a house like this to Hawthorne.