My "10 year project": rebuilding an efficient "tiny" crooked house in Canada

MN Renovator · 03-07-12, 07:17 PM

It would be twice as much work considering you'd have to open the exterior and interior sides separately to fill them. If there really is 12" total all around then that's around R40, but then you have to remove the space taken up by the siding, the stuff inside the gap, and the thickness of the wall etc. I'm not sure what's all in there and I don't know if you've had a chance to check it out. Then again an R40 wall might not be cost effective over a very long time anyway. Then again, I did create a 500sq ft house on paper that could be heated with 5000BTU 1500 watt space heater at -14f(-26c) if it could be built with nearly zero infiltration and when it gets that cold the ventilation was turned off. I had too much time on my hands though but the walls were 2x6 filled with cellulose with a 2" XPS R10 sheet outside(R30 walls) and R75 overhead. I guess my point is that it didn't take too much insulation in the walls, so a 12" wall might do quite a bit.

03-07-12, 07:17 PM	#11
MN Renovator Less usage=Cheaper bills Join Date: Nov 2010 Location: Minneapolis, MN Posts: 939 Thanks: 41 Thanked 116 Times in 90 Posts	It would be twice as much work considering you'd have to open the exterior and interior sides separately to fill them. If there really is 12" total all around then that's around R40, but then you have to remove the space taken up by the siding, the stuff inside the gap, and the thickness of the wall etc. I'm not sure what's all in there and I don't know if you've had a chance to check it out. Then again an R40 wall might not be cost effective over a very long time anyway. Then again, I did create a 500sq ft house on paper that could be heated with 5000BTU 1500 watt space heater at -14f(-26c) if it could be built with nearly zero infiltration and when it gets that cold the ventilation was turned off. I had too much time on my hands though but the walls were 2x6 filled with cellulose with a 2" XPS R10 sheet outside(R30 walls) and R75 overhead. I guess my point is that it didn't take too much insulation in the walls, so a 12" wall might do quite a bit.