Hong Kong: the city where most people live in shoe box-sized apartments that make those in New York or London look palatial — and yet still wins the title of least affordable housing market in the world.

It is an accolade the former British colony does not wear lightly. Here, where the most modest flat will set you back at least $1m, developers — ever eager to maximise income — have worked out that you can make apartments smaller still — at just 500 sq ft — and access a slightly less well-off pool of buyers.

But cracks are appearing in the bricks and mortar. Price tags are rising to new, and ever less sustainable, heights. A combination of curbs on foreign buyers and tightening capital controls in China — the money tap that has buoyed up property sales from Sydney to London to New York — are starting to temper the rush to buy.