The Chinese firm's latest project, Tubular Living, is probably its wackiest yet and suggests that people make their home in large metal ventilation shafts.

Though Tubular Living could be seen as a dystopian vision of living in over-crowded cities, it shouldn't be taken too seriously. The project was commissioned by the Lane Crawford retail company to celebrate 165 years of operation, and three different installations were constructed in Beijing, Shanghai, and Hong kong department stores last year.

PAO says that its tubular micro-housing could be easily manufactured with standardized factory methods. The units created include staircases and dining furniture, though whether or not anyone would want to actually live in one is another question – we'd guess that you'd feel like a human sardine, and would be driven to distraction by the inevitable amplified snoring at night from neighboring units.