I honestly can't be bothered cropping this picture because I've spent the past god-knows-how-many hours working on this and I need some sleep.
Anyway, here's the Books and Branches Library, aka Twilight's house, aka the library that's never actually used as a library.
This was... difficult. Most of the buildings in Ponyville seem to suffer from TARDIS syndrome - they're a lot bigger on the inside than they are on the outside. The library has five floors, two floors underground and another 4 floors extending up to the telescope balcony at the very top of the tree. It's slightly smaller than the Town Hall, which is a huge relief, and hopefully you can see how it compares to some of the other buildings in the screenshot.
The very top floor has no roof, instead it has 5 oak trees placed around the floor. The walls cover the trunks of the trees, and the leaves poke out over the top to make the house looks like one big-ass tree!
I'll upload some interior shots when I've finished inside. At the moment I've only furnished the bottom floor, so the rest of the hose is looking quite empty.
Extreme credit goes to
for their maps and layouts of Ponyville and its buildings, they were EXTREMELY useful. There area couple of small modifications to fit the game's limitations, but other than that the building should be identical to the one you see in the show.
MLP belongs to
The Sims 3 belongs to