In Portland Oregon.
Before: House had large (high) crawlspace. Pony stud walls and foundation walls were insulated with foil backed 3 1/2" insulation. No insulation between floor joists. I assume it was foil backed due to fire codes for "exposed" insulation.
After: Dug out crawlspace. Constructed new mini-foundation (about 4 feet high) inside a few feet of the existing foundation. Poured concrete slab floor. Built new stud walls inside the new mini-foundation. This means these stud wall are around 4 feet from the original pony stud walls and original foundation.
Question. How do I insulate these new basement rooms (game room, bedroom, office) to meet code?