Cob: cob over traditional house?

[Melanie Kleiner]

I was wondering if it is possible to apply cob over an existing old farmhouse (it has that nasty asbestos slate siding now).  There are many cracks and drafts and I thought it might be a less expensive way to reside the house.  Plus I love the look of cob and we could add on to the house with cob.  Any thoughts are welcome!