People's Microclimate and Mobility Problem
Only small part of Earth is truly habitable without housing. The perfect conditions for living could be achieved by modification of climate (e.g., for humans, it's making the cities of room-temperature, clean and comfortable), or by increasing the availability (and desirably -- mobility) of housing. Currently, the comfortable environment (e.g., home) does not move together with a person.
This is a general problem. One aspect of this problem, is, for example the problem of refugees, the number of whom is estimated by the UNHCR to be around 19.5 million in 2014, and expected to grow.
Ideally, we want to travel while working. We want air-conditioning and isolation from polluted air and dangerous insects and animals, and airborne diseases common on this planet, protection from cold and hot climate, we want ad-hoc formation and destruction of buildings for friends to meet, discuss, and socialize. We want a ubiquitous reusable lightweight universal structure for all of that.