Tuesday, 4 December 2012

Team Tortuga

Our trip back from Turtle Falls yesterday after having met with our building "team" was as if we were living in some weird Eagles songbook version of life...life in the fast lane of the westbound 401 was leaving us with a peaceful easy feeling. I swear no mushrooms were harmed for the writing of this post. Let me explain...

First let me introduce our team of extraordinary gentlemen. These are the enthusiastic and brilliant minds bringing passive house Casa Tortuga to reality. Hmm...all handsome AND handy. Red Green would be proud of our ability to assemble such an excellent team!

L-R: Stephen Magneron (Homesol Building Solutions Inc.), Mark Raison (Crane's Building Service),
Ross Elliot (Homesol Building Solutions Inc.), Chris Straka (Vert Design Inc.)

Yesterday's meeting brought everyone together to discuss construction details and determine what trees still need to be removed to allow for maximum solar gain. As you can see from the photo there are a lot of trees at Turtle Falls. Although a good number of trees met lumberjack Alistair's chainsaw a couple of weeks ago, there are still a few more to be introduced to said chainsaw. Stephen got right to work setting up the Solar Pathfinder.

Stephen levels the Solar Pathfinder in the excavation site and makes sure it's oriented to solar south
Then he takes a picture of the instrument's reflection of the sky
The reflection of the skyline in the Solar Pathfinder shows which trees need to be removed to allow maximum solar gain

The simplicity and brilliance of this instrument is mind boggling...nothing electronic, no batteries required, just a compass, a tiny bubble level, a graph/grid of the correct latitude for the area and a glass dome. The grid under the glass dome represents the sun's path (horizontal arcs) for every month of the year for our particular latitude (44 degrees N). The vertical lines represent time of day. The important times for sunlight hours for solar gain are between about 9 or 10 am to 3 or 4 pm. So if you look at the reflection of the trees on the grid lines between about 9:30am to 3:30pm, those are the trees needing to be removed. We were nicely surprised, and relieved, that we only have to remove about 10 pine trees. There's a fine balance of sun and shade required to passively heat and cool a house. The deciduous trees will not need to be removed since they will provide shade in the summer. In winter, they lose their leaves therefore they allow sunshine through. Brilliant!

There is a whole other side to the Solar Pathfinder that is way more high tech. The above photo gets loaded into a computer program that then allows for all kinds of analysis necessary for the energy modelling of a passive home. I'll leave you to investigate that on your own if you're interested...it's pretty high-end geekish best left to the high-end geeks to explain. Me, I'm just a low-end geek and it's beyond my capabilities! That's why we have Stephen and Ross from Homesol on board.

Priscilla's conference room holds 6...no problem!
Next, we all squeezed into Priscilla's conference room to discuss the details of foundation and wall construction, moisture barriers, air sealing, insulation choices, how to hang the deck to minimize thermal bridging, and window placement within the wall. Did you know that it makes a difference to the amount of heat gained through the windows whether the windows are installed closer to the interior or exterior of the wall? Ya...me neither! And since the walls of this house are going to be somewhere close to 23 inches (58cm) thick, before exterior cladding is installed, there's a lot of room to move the window in or out. Crazy stuff. My vote would be for more solar heat gain (cuz I really, really dislike being cold!) but I'll leave that up to the guys and their PHPP computer program to figure out what the best average would be for heating and cooling. Ras and I heard so many new names yesterday...blue skin, black jo, polyisocyanurate, xps, siga, yadayada...I'm glad we weren't being tested at the end of the day. That's why we have contractor Mark on board!

I'll say that it was a great meeting. The guys brainstormed about the best ways to construct this air tight house, debating option after option to reach our goals in the most cost effective and energy efficient manner. Ras & I were there to answer ya or nay to material choices...do we go with spray foam insulation with a high carbon footprint or do we choose the dense-pack cellulose option with less R-value per inch but more environmentally friendly (yes to the latter), if we have to add posts under the deck as opposed to cantilevering what is our preference. Cantilevering causes problems with thermal bridging...so lets explore the post option. When the brainstorm session concluded, Ras & I had a much deeper understanding of the why's and how's of passive house logic. This will be the first passive house that Mark has built so he is now feeling more confident about what needs to be done to get us to passive house certification. The seemingly odd techniques of over-insulating are making sense to him now. Mark has made the leap, with relative ease, from conventional building code compliant techniques (although he has always built to a better standard anyway) to the energy efficient building techniques of the future. Notice in the photo above how we have him surrounded and barricaded in the conference room...just in case he still had the notion to run screaming for the hills ;)

Finally, to make sense of the Eagle songbook reference...as we were in the fast lane zooming back to the city after this meeting, we both had this overwhelming sense of calm. You would think our heads would be spinning and there would be at least some anxiety about the scale and detail of this project...but no. That is a sure sign that we have assembled a great team that gives us 100% confidence in what we have decided to build at Turtle Falls.

'Cause I got a peaceful easy feeling,
And I know you won't let me down
'cause I'm already standing on the ground.

More later,