Cage housing, Hong Kong. Cage houses are a type of 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. Sometimes the units are subdivided with plywood into smaller cell sections. 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.