I’m an intown renovation contractor. I have a client with a throwaway basement room who wants to put in a hot yoga studio. Low ceiling.

4 walls: windows on one wall with 2/3 below grade foundation wall, full height (7.5’) foundation wall below grade another, new framed wall with custom door(?) 3rd side, and masonry interior wall 4th side.
Wondering what preparatory steps to take for each wall type-before lining with T&G cedar.
Thanks!