From your examples:
Esta casa es mía.
Esta es mi casa.
The meaning is the same. I would say that example 1.) emphasizes more who does the house belong to. Pretty much like my and mine, I believe?
I would use 2.) in a more casual way, something like Look! This is my house whereas 1.) is more for This is mr. Smith's house, that is mrs. Robinson's, but next house is mine.
