All the interior seems to be strapped. Leaving space for most wiring and plumbing supply iines. The strapping also holds the top row of building blocks that anchor the roof.

Possibile code violations. Did not see the first row of blocks anchored to the slab. May have just missed it. It is convention to use various particle and chipboard products in our region. I really never have liked them.

They are used of course because of them being economical. I dislike them so much. I will not even use them on a storage shed.Or for bases of kitchen cupboards. Any water ingress can spell a major issue.

Any plywood sold in Canada 1/4 inch thick or greater. Must incorporate waterproof glue. Douglas fir plywood is highly rot resistant and very strong.