Re: Unusual application of stucco... need advice!
The metal siding will need to be removed and the walls prepped for stucco. Depending on how they're framed, it may be as easy as installing wire lath and applying stucco, or could require sheathing before the lath.
Personal note, I am not a fan of the current methods of stucco, which involves a 1" layer of foam and barely a scratch coating of stucco over the surface. This method, while more energy efficient due to the foam insulation, is an extremely poor and delicate style of stucco, as the plaster is barely 1/8" thick, making it prone to cracking and impact damage from something as minor as walking by the corner of it. If it were my house, I would demand the old style of stucco that was 3/4"+ thick, this is a much more sound and durable surface.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!