Hello, I have been long contemplating a renovation (pretty major!) of a residence. It dates to 1938. The question is regarding the outer wall structure and how best to insulate (if possible) and repair plaster faults. As the title suggests, the structure is a terra cotta structural tile block core with a standard exterior brick veneer, and then the interior is plaster directly upon the structural tile. As can be expected, there is no insulation beyond the dead air space created by the hollow core of the structural tile. For those not familiar with structural tile it looks like this: This is pic nabbed off the net and is about the exact tile we have. Note the grooves (to which the plaster adheres) indicate the extrusion direction of the tile and thus the hollow core structure. Ours are alternated every other block vs. course you see here. The block and brick are in excellent shape with only minor exterior tuck deterioration. There's the animal now: Can interior furring and urethane foam board + vapor barrier and then dry wall be attached to this structure (similar to some basements)? How? I have read how brittle this material is and drilling may create a "blow out" hole exit substantially weakening the block. You wouldn't want to simply "glue" and interior to this would we? IF...if it were insulated from the interior, what is the risk of freeze thaw to the exterior veneer? I gather this is an issue with multi-wythe brick structure...but this is not brick! BTW...it is in SW Ohio. Is there an alternative insulating method we have overlooked? Thanks in advance for suggestions!