A client recently asked me, out of curiosity, how high up and down she would own when her first home closed. Essentially, at common law, you own “up to the heavens and down to the centre of the earth”. That being said, in many jurisdictions there are limits that have been placed on the common law rule.
In Ontario, whether you own down into the earth depends on whether there are mining or subsurface rights held by another entity (including the Crown, which owns mining rights in a large part of the north). If no one owns the subsurface rights, then you own to the midpoint of the earth – where the person on the other side of the planet takes over.
Above your house is a little trickier. While you do in fact own all of the air directly above your roof, there is no right to light or a view of any sort in Ontario. So you could, in fact, have all that space, but the apartment next door could entirely block any use of it.