Leeds411: male indigenous villagers have had the right (since 1973) to receive a plot of government land on which to build a small house (2100 sq ft max, usually arranged in 3 floors). This was before the border with China was opened in 1979, and the policy was intended to help farmers out by ensuring their families had somewhere to live.
Now of course, not much NT land is farmed, and the policy is an anachronism. But villagers can make a lot of money by letting or selling these houses, and they have come to regard it as a birthright. Thus former agricultural land is dotted with these three-storey houses, often built without any access or sewage facilities, because they are exempt from planning laws. The policy should be abolished but the Heung Yee Kuk (villagers' group) is a powerful lobby.