It is possible to attach studs directly to the facade with screws. I sawed off the lower part of the facade and installed an extra sill plate and insulated 70mm, use windproof paper or equivalent, and extend the roof for a nicer look.
As already mentioned, check the floors, see if they sag (not good), I have ripped out five floors, check heating pipes to ensure there are no leaks in the fittings, if they are the ones lying on the floor, it's a heck of a hassle if you need to repair them.