For some young single people who earn very little, subdivided homes are the only option when they can no longer stay at home because of family problems.
But living in cramped conditions, sometimes without windows or air conditioning, can end up making things far worse, a survey by the Society for Community Organisation found.
For the past six months, Peter Ng, 29, has been living in a claustrophobic cubicle of less than 20 sq ft in Tai Kok Tsui.
He left his family home because it was too crowded, with various siblings and relatives all living there. And he wanted to live somewhere closer to the call centre where he works.
"I feel like an animal living in a cage. I find it difficult even to turn around in there," Ng said.
Beyond his cubicle, Ng shares a toilet with 10 other residents.
His sleep is constantly disturbed by coughing and noise from the other tenants. Ng said it was a depressing environment to live in. One of his neighbours, who was suffering from depression, committed suicide.
Ng pays HK$1,400 a month for his cubicle in the old building - almost one-fifth of his monthly income of HK$8,000.
"Before I moved in here, I lived in a factory building. The environment was even worse," he said. He moved out because the emergency fire exits in the building were blocked. "But I'm not optimistic about finding a better place to live," he said.
Ng recently applied for public housing. However, given that he is young and single, he will likely have a long wait ahead of him. With 106,900 young, single people in the queue at the end of last year, social workers put the wait for new applicants at 10 years.
Given his living situation, Ng said he can't even think about starting a family. Many of his friends have married on the mainland for this reason, he said.
Of the 113 people polled for the survey, half of them said they avoided inviting friends or family to visit them. All of them lived in subdivided flats, were on low incomes and were young or middle-aged and single.
"I got divorced last year. My children don't know I'm living here," said Henry Cheung, 51, a cleaner who lives in a 20 sq ft cubicle flat in Sham Shui Po.
He had to move from a bigger subdivided flat six months ago because the rent went up.
When courier Chan Chi-kwong, 39, applied for public housing in 2004, he thought he would be waiting for three years at most, as had been guaranteed by the government.
But the next year a points system was introduced that pushed young, single applicants further down the priority list.
In fact he was still waiting until this month, when he received a letter from the Housing Authority - but it was not good news. Chan's application was rejected because he did not meet a housing officer when asked to do so. He says he never received the letter and plans to appeal.
The annual public housing quota for single people who are not elderly is 8 per cent - but they made up 48 per cent of the queue at the end of last year.