On our recent trip to Hong Kong, we learned about the precarious housing situation that is harsh reality for a few hundred thousand people there. The so-called subdivided units are a special form of housing in Hong Kong nobody likes to speak about. Once regular apartments, they were divided into multiple units, mostly in an illegal manner. Some provide as little as ~4 square meters (40 square feet) of space for people to live.
The Wikipedia article states that
Subdivided flats (also called subdivided units) are a ubiquitous type of rental housing found in Hong Kong. They are flats divided into two or more separate units to house more people. The flats' original partition walls are usually removed, and new ones are erected. New toilets and kitchens are installed, and internal drains are added or altered. These updates can compromise the building's safety and hygiene.
It is estimated that 280,000 people live in subdivided flats or other similarly undesirable conditions, mostly located in old residential buildings. Many subdivided flats are even smaller than prison cells in Hong Kong. According to a study by the Society for Community Organisation, people living in subdivided flats are mainly unemployed citizens, low-income families and new immigrants. The median living area per person of a subdivided flat was found to be 40 square feet for small suite and 30 square feet (2.8 sqm) for cubicle in 2009.
In the following pictures, each A/C unit seen from the outside represents one apartment (and some have none), where sometimes multiple people live.
Since these flats obviously lack sanitary spaces, their inhabitants are forced to use public sanitary spaces such as this public sport center:
The following buildings probably do not host subdivided units, but they don't look much more inviting (or providing much more living space per unit) either: