Cyborg Habitat
The habitats are cyborgs. In other words, we would live inside cyborgs. It created by implanting cybernetics (i.e. mechanical parts) into an existing/mutated living organism. The organic part could be composed of parts from different living creatures, similar to mythological creatures.
Taking advantage of the flexibility and adaptability of living biological systems, it has the ability to cope with the most complex environments. The incorporation of cybernetics into the living organism would amplify such advantages. Unlike living organisms, which generally evolves over a long period of time, the cyborg can rapid adapt to any enviorment, allowing the cyborg habitat to survive almost any environment. It has the ability to function properly even under the most devastating conditions. It adapts to the most extreme climate conditions. Because of its wonderful flexibility, it can be a water/land/air habitat. Moreover, the incorporation of cybernetics and mechanical parts molds the cyborg into a comfortable and pleasant habitat.
The habit could be powered by flexible sources of energy: like living organisms, it can physiologically assimilate, transforming various food sources into energy by anabolism and metabolism, or it can sustain itself by solar power when no food source is available.
The cybernetic implants are essentially self-replicating nanobots. It parasites in the living organism; it functions and replicates in mechanisms similar to those of viruses. Via implanted cybernetics and networks, the function and behavior of the cyborgs are controlled by humans. Like biological organisms, the cyborg has the ability to reproduce. Like certain viruses can be inherited by a child, the reproduced cyborg contains the nanobots implanted in its parents.
The design is inspired by the Borgs from Star Trek. (http://en.wikipedia.org/wiki/Borg_%28fictional_aliens%29)