The key to small-space living is not feeling cramped, which makes this Barcelona apartment the pinnacle of the genre. The home uses sliding doors to open the 430-square-foot apartment up for a sense of space, or close it for privacy. But the centerpiece of the house is the hole in the ceiling — a plant-filled half-outdoor shower that’s built like a chimney, open to the sky. (Don’t worry — there are camouflaging plants on top, so the drones will have to work VERY hard to see you naked.)

Even Barcelona can get a bit chilly in winter, so it’s possible to close off the outdoor half the shower so you don’t have to expose yourself to the elements. But in summer, you can stand among the plants cascading down from the roof, and even shower in rainwater like Big Bird.

The sliding door effect is cool too, since it essentially gives the apartment four different floor plans: a combined bedroom/living area with a closed-off bathroom; a combined bathroom/bedroom separate from the living room; separate bed and living rooms with a closed-off bathroom; or an entirely open space. But realistically we’re betting the residents spend most of their time in the shower.