Planning a 2nd story addition to a 1940s house with CMU wall construction, plaster on the inside and stucco on the outside.  Thinking of some thickness of polyiso on the outside (2″ min) and maybe something on the inside.  The wall, including stucco and plaster are in great shape, but must insulate. To insulate well, the walls will become quite thick.  The other extreme option is demo of the walls but that’s a lot of extra scope.  Welcome to any thoughts.