It is too bad that Detroit's Kelsey-Hayes Corporation is no longer around; they had something going with their prefab shelters in 1963. We like this one's multifunction space with efficient storage under the beds. The green roof will keep it cool and inconspicuous.
We often talk about how we need to increase the population density of our suburbs; perhaps this is the answer: complete, self-sufficient, soundproofed little basement apartments. Fireproof, in case your landlord stores jerrycans full of gasoline nearby. With separate ventilation so that you can smoke away without disturbing the people upstairs. What efficient use of space.