Cage housing, Hong Kong. Cage houses are a type of stacked temporary accommodation that exists in Hong Kong, one of the most crowded and densely populated cities in the world. The rooms are cramped cage-like units, large enough for a bed and a few possessions, but little else. Other facilities will be shared with other residents. Originally built for construction workers, these units have become the long-term home of some of the poorest and most vulnerable in Hong Kong society, including the elderly, single people, the unemployed, ex-prisoners, and economic migrants.