On April 20, 2021 at 21:31, mrtristan said...
Worked on a few houses like this here in Collingwood. Agree it was a pain to wire. The builder always had an electric melting device that slices through the foam like butter. I always thought that kind of construction would cost more but now you've got me thinking about the option.
The hot knife is alright as its less cleanup, but if having to run horizontally you still need something to cut the ribs with (unless you really plan your horizontal runs where the block seams are). We have an electric chainsaw with a couple pieces of wood bolted to the the bar about 2.5" from the end for a depth gauge. This allows you to cut the ribs if needing to go horizontal and give a nice opening for vertical runs to stuff wire into it.
I don't know if there will be much in savings (if any) but the fact that the exterior is completely sealed with no way of bugs/critters getting into the house is a bonus. You don't need to worry about insulation/vapor barrier (except for the attic, but there is a way to make that a conditioned space also).
The downsides are they aren't easy to fish wires in after, and per OBC (Ontario Building Code) your exterior basement walls have to be drywalled to stop the foam from creating toxic fumes in the event of a fire. So if you weren't planning on finishing the basement right away you still need to plan to drywall those walls.
I would just hang the drywall and not mud/tape and have your electrician plan for bare minimum electrical with surface mount boxes and extra wire coiled in the ceiling. This way you still meet codes and allows you to re-use the sheets when ready to finish as its easy to remove them and re-hang them and can plan for receptacles without too much additional work in running new circuits
