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.`