We love transformer designs that serve multiple functions and take up less space. We also have shown a lot of green modern dollhouses. But the problem always comes up- where do you put these things when you are not using them? They can take up a lot of space.
Japan's Torafu Architects solve this problem by making their dollhouse design fold up and turn into a chair. They tell Designboom that "combining storage with external functionalities is always a matter in question when it comes to children’s furnishings and toys." As a dollhouse it is a lot less detailed than many we have shown, and requires a bit more imagination. That doesn't seem to be a problem. Lots more images on Designboom.