The reason this particular transition works so well is because the house is in the exact same position in both the outside and inside levels. (i.e. in both levels the door is at 29,51).
If you were to try and recreate the same effect on an actual server some buildings would cross over a level link, and then in order to retain the same effect the inside would need to be split across levels as well. Which isn't really as feasible.
It is cool, but it'd be much cooler to just have the "inside view" on the overworld, and use an image that fades when you're near it for the roof of every single building.
