Bart's Tree House is a custom treehouse owned by Bart Simpson. Upon its construction, he is unlocked. The Tree House unlocks at Level 12, and was originally the only Level 12 quest items to build until the Library was introduced at a later date with Martin. When you build the treehouse you unlock the third cutscene. The Tree House is a somewhat different building, and is even considered to be more of a decoration. The building does not provide income, nor can it be interacted with directly in any way. It is also built instantly, much like decorations. When moving the Tree House, it even has the same properties as a decoration, however, the Tree House is included in the Buildings section rather than in the Decorations section. This is most likely because Bart comes with it.