Foam is going to be hard to work with. The concrete will be hard to contain with foam. Whatever you use to support the foam will have to be really massive (solid backing) or really close to the floor (short span). If you do figure a way to use the foam, you may consider termite proofing the foam before pouring the concrete. Termites could possibly find their way up between the foam and the concrete. Foam is being used behind foundation walls commonly here, but the forms go on right over the foam. OR, the foam is added after the pour.
Vents by USA code have to be 1 per every 150sqft of living space. I have no idea what Canada requires. With the vents closed in the winter, you will notice a difference.
Sealing the top of the wall to the sill log?
Chink chink chink.
Newer log homes don't use chinking. You will have to do something. Maybe flexible foam backer rods then caulking. The answer will come to you when the time comes. If not, feel free to discuss it with us!
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