In Hong Kong where the cost of living is sky-high, rethinking what home looks like may help the city's least fortunate.

A refashioned concrete water pipe is called an "Opod."

While it may seem small the architect behind it believes these are a perfect solution in a city where some sleep in spaces smaller than a closet."

"We can actually try to use land that is not currently suitable for conventional development. So what are these pieces of land? So sometimes there's land leftover between buildings which are narrow so it's not easy to build a new building, we could put some OPods in there and utilise that land that could be right in the centre of the city," he said. 

Across Hong Kong, housing prices and a lack of land are pushing developers to design so-called "nano flats" to meet demand.

These can cost far more than an increasingly popular alternative, shipping container homes popping up in the city suburbs.

But living in containers or Opods is actually illegal.

So far officials have tried taxes to fight the housing shortage with mixed results, and until recently they've been reluctant to allow prefab housing. 

By one survey, Hong Kong has been ranked the least-affordable city in the world- for a few years running.

The waiting list for public housing is now at a record high of up to four-and-a-half years.