I am just finishing up my dream shop. I am working on my second dream house.
I'm in Michigan, and used to live in Ontario, so I know about cold weather.
The shop is 30' x 70' with full 12' ceiling, and still not really big enough. You could plan for an addition if you can't swing the full deal all at once.
The walls are a foot thick and r-50 blown in cellulose. It uses a double wall construction, one inner wall of 2x4's and a completely separate outer wall, also of 2x4 construction. this provides a thermal break in the wood framing. In conventional wood framing, the wood itself is a significant source of heat loss. The ceiling has 14-18" of cellulose blown in. The slab is 6" thick with 4" of high density foam under it. The perimeter of the slab is also insulated with foam. A more or less perfect 6 mil ply vapor barrier, and tyvek all the way around the plywood exterior sheathing. Full drywall, taped and mudded. It's very airtight.
There are only two windows (one on the north, one on the south,so I can weld inside with fans. One man door and one 18' very expensive roll up garage door. I bought the best insulated door I could get, r-24, and plan to glue more on later if needed.
So, my shop is ~2,000 square feet. I heated it all winter with a 1,200 watt electric heater from wal-mart ($20), and it was set on low, not high. It used a measured 800 watts. In Nov-March, it never went below 43f, and was usually 46-50. I unplugged it for a week and never dropped below freezing, despite very cold ambient temps. I use compact fluorescent lighting. Theoretically, I could heat the building by installing incandescents and just leaving them on in the winter. In the summer, it has enough ground coupling that it stays amazingly cool. You would swear it's air conditioned when it's 85-90 outside, and 78 inside.
I cannot recommend enough, very high levels of insulation. It will save piles of money and fuel for decades and decades, and you only have to pay for it once. The resale value of your building will also go up much faster than the neighbor's place once fuel costs go sky high.
This form of superinsulation is not that expensive, since you use 2x4 framing on 24" centers and you can make the wall as thick as you want. It is significantly more effective than using 2x6's, because the 2x6's leak heat like a seive.
Cellulose is not that expensive either, and much more effective than fiberglass. It will settle in the wall cavities for 6 months, so you have to plan on blowing it twice to top up before you seal all the holes. You also don't need a furnace. If you build a house like this, a typical domestic water heater provides enough heat to keep the house comfortable.
Finest regards,
troy
