How much space is needed for stucco. I am hoping to build a shipping container home with stucco siding. The question is how many inches of outcropping is needed for stucco?

There are several different ways to do 'stucco', involving different thicknesses.

Traditional stucco uses a lathe wire as a base, this lathe wire is attached to a sub base. Total thickness of lathe wire and 2 to 3 coats of stucco is going to vary but will be about 1/2" to 3/4"

Stucco on top of foam (EFIS)uses 2" foam with a fiberglass mesh, stucco base layer and stucco top coat. Total thickness is about 2-1/4".