Hong Kong is a city with one of the highest population densities in the world; it is so built up that the only way to go is vertical and this is why virtually everyone lives in a high rise building. The more recent the building the higher it is.
For technology companies wanting to build an App that allows users to quickly search for buildings in Hong Kong with Geo-code, English and Chinese support there are very few options. The Lands Department produces a book in PDF format with this information which is reasonably comprehensive but virtually useless to tech companies because the information is not searchable and does not contain any information about the co-ordinates of the building. So for tech start up wishing to integrate this information into their applications it would be impossible.
OneDay (搵地) has compiled a buildings database for Hong Kong manually over the last 6 years and all of the information is Traditional Chinese and English, along with transport links, building photographs, Google Map and Baidu Map codes.
The
OneDay (搵地) Buildings API system for Hong Kong can be found here:-
https://www.oneday.com.hk/en_US/developer/transport/