Evel
You are right with conventional construction there is less chance of the average framer messing up, and if he does make a mistake its easy to change. (If someone catches it) If I were to make a high performance home I would lean toward the ICF. The structure will be very well sealed by the nature of the construction. There would be no thermal bridging you get with the traditional stick construction. I like you idea of the stucco /EFIS finish. For the higher R value you may be after one can just screw rigid foam to the outside of the ICF blocks. With the ICF you start at the concrete footings and keep laying them until the truss plate no area for the smallest location for air infiltration.
If you can do most of the grunt work such as laying out the tubing for heated concrete floors, DIY your solar hot water panels, and installing the tubing for the ground source heat pump you can save lots of money there and have heat and air-conditioning for practically zero. Add in some solar PV and you probably could get to zero. Its very attainable but it isn't a free lunch.
The solar input through the windows will not be near enough. We have black tile floors and yes where the sunlight strikes the floor it becomes warm but else-were is cool and can become uncomfortable cold. Heated concrete slab is the Cadillac of space heating.
I will leave you with this: On cold mornings where wind is howling outside. -20C I can be standing, bare foot looking outside at the wind swept snow drinking my coffee. The floor is at 28C and the house temp at 23C toasty warm from the heat I had collected the day before from the solar hot water running through the concrete that has lasted through the night. And it was free!! It totally do-able
Randen
|