Here's the front of the mansion (see that tiny doorway in the front, that's about the size your character will be):
Once you walk in, you get this view (interior isn't complete):
From upstairs it looks like this:
In the middle of the building is a outside courtyard (this is looking down from the roof:
And finally in the back of the mansion where there will be a lush garden:
So as you can tell, I've spent a fair amount of time on the details, adapting about 12-15 pictures of actual mansions with features I liked. The inside shouldn't take me too much longer, and then I will add chandeliers, huge fireplaces, etc. Really "Citizen Kane" the hell out of the building.
If you don't know what Citizen Kane is, it's a movie. Go watch it.