Earthships and Cob Houses
Earthship: A home built entirely (or primarily) out of renewable/recyclable materials (like sand, mud, certain types of wood and foam, straw, tires, bottles etc.). Often able to sustain habitability with its own food/water/solar power. Cob Houses: Houses made of cob, a mixture of straw and clay. Material is wet enough to be able to form different shapes, but dry enough to build with.
Wooden Sleepbox Pods are the next big thing, and their latest location comes to you by way of Belorussky Railway Station, in Moscow. With less than 60 rooms total, these spaces fit into tight quarters and house the necessary elements of a comfortable stay. A TV, mirror, storage, and of course bed all fit into the rooms while the bathroom pods are shared between floors.