When you build a house you go through alternating phases of panicking that the house is too big and then too small. When the hole was first dug it seemed enormous. Then they poured the foundation footers it seemed really small. But then the foundation seemed really big. Now the walls are going up and the rooms seem so small.
The concrete forms for the basement window well
Framing the Basement Walls
I met today with a solar contractor. There are so many decisions to make on a solar hot water system: flat-plate vs evacuated tubes; pressurized tank vs unpressurized; drainback vs closed-loop. And then there are decisions regarding size, heat dump capability, and whether you want to have the system connected to your in-floor radiant.
Click below for my preliminary decisions based on my research so far.
The house continues apace. With the foundation walls up, Mark turned to preparing for the basement floor. First he put in the necessary pipes for the basement (bathroom, laundry drains, sewage pump). Then he added the radon mitigation system. On top of that went a few inches of gravel and then my custom-prepared 6 inches of styrofoam.
The standard in construction is two inches of insulation under the basement slab, but that didn’t strike me as nearly enough. The ground is about 50-55 degrees, about twenty degrees below the interior of the house. That’s already a fairly big gap–but it gets more dramatic. I’m heating the basement with in-floor radiant heating, which means that I will have 90-120 degree water flowing through about 1,000 feet of plastic tubing in my floor slab. The floor heats up and slowly transfers its heat to the room. With only 2 inches of styrofoam, however, I was worried that a significant portion of that nice, expensive heat would go to heat the earthworms.
My battle to get a thicker insulation under the floor slab was an interesting case study in the power of the status quo. At first, both the architects and my builder balked at the idea. Too unsteady! they said. Throws off the design! Not worth it! Not even available! I insisted, hwoever, and so Mark called around to some local styrofoam suppliers. Long story short, it turns out that a local company was happy to specially manufacture some 6″ foam sheets that cost barely more than the standard 2″. And after Mark installed the thicker sheets, he said that due to their greater rigidity they were even easier to work with than normal styrofoam.
Anyways: with the foam down, the plumber came and put in the radiant floor tubing and then Mark poured the foundation. Now we have a clean, beautiful basement, ready for interior wall framing.
We also have the season’s first snow.
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- basement piping goes in first
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- foamhenge
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- the black waterproofing on the foundation is water-based. go figure
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- southside basement windows–let there be light!
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- finished basement overview–note the 3″ of styrofoam on the outside of the basement
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- the southside lightwell for the basement windows
Another exciting step: foundation walls:
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- the rebar is up; the forms are next
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- the empty forms
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- inside view of an empty concrete form
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- smoothing the wet concrete in the form
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- Foundation with the forms removed
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- Foundation with the forms removed
Here’s a list of the green / renewable / efficient ideas we plan to incorporate into our project:
1. Urban Infill Location. The lot is 6 blocks from Main Street. There are way too many people chewing up the Montana countryside with their 5-20 acre ranchettes, in our humble opinions. As the bumper sticker says: “If you love Montana, Live in Town.”
2. Heavily insulated foundation. We were going to use Insulated Concrete Forms (ICFs), which are essentially big foam forms that you stack up like Legos and then pour concrete in between. But the bids showed that an ICF basement would have cost us significantly more than a traditionally poured one. (I don’t think that ICF basements are always more expensive, it just turned out that way with our selection of subcontractors.) So we will effectively replicate an ICF basement by putting 3 inches of polysterene insulation on the outside of the basement, and 4 inches of sprayed foam on the inside. (That’s one inch more than we would have had with ICFs.)
3. SIPs. Structurally Insulated Panels replace traditional stick-frame walls. They are essentially big slabs of insulation with OSB (oriented strand board, a stronger plywood) on either side. It eliminates the thermal bridging that wood studs have. It also makes it easier to make your house airtight. You can make your house as tight and well-insulated with a stick-frame wall, but SIPs make it easier. They also uses a lot less wood. It turned out that 6 inch thick SIP walls cost only a little less than 12″ ones, so we’re getting 12″ thick walls. Should be about R-45.
They came and poured the footers today. The very first physical part of the actual house. We feel like new parents all excited about every ooh and ahh from their newborn. Fascinating to us, of exceedingly dubious interest to anyone else.
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- footers get poured
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- Let’s be concrete
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- That guy on the right is controlling the concrete wirelessly
When I started researching green building–starting with basic questions, like, what’s so “green” about building something with virgin raw materials when the landscape is littered with existing structures?–I quickly came across the Passivhaus movement in Germany. English writers use the German word instead of translating it as “passive house” supposedly because in the 1970s the idea of a passive house meant the passive solar house, a building that heated up in the sun during the day and released that energy into the house at night. Personally, I think they use the term because it sounds a little like Bauhaus, which, even if you have no idea what it means, sounds like it means something futuristic, nerdy, and smart.
Well, we’ve gone and done it. From what it looks like now, maybe we should quit while we’re ahead and just put in a swimming pool?
From the street
Mark Prince (our general contractor) on his way to China
Backhoe at work
It was fascinating to see how thin the layer of topsoil was. Below that, it’s all rock, apparently from the lake that once covered this area. Watching the backhoe work was incredible. This thing moves!
If we’re going to build a house I want a cool photo record of it. But we would like to avoid having a thick scrapbook of photos we bore guests with. So I figured, why not make a 30 second time lapse video of the construction process?
Here’s the final setup of my time lapse photography setup. To read the details read on below.
Construction Time Lapse Photography setup
