There are a lot of different sci-fi houses, and here is my own modular one in 15mm scale. Each floor is one small flat with small toilet/bathroom (only room, no accessories). With holes for 3x2mm magnets.
I haven't print it yet (I have finished it a few moments ago), but it looks like printable without supports.
enjoy
ground.stl | 999.0KB | |
middle.stl | 1.2MB | |
roof.stl | 119.5KB | |
upper.stl | 1.2MB |