There are about 2,000 odd industrial properties in Hong Kong in total and this number is not expanding. Many of these were built between the 60s and 80s when Hong Kong was still manufacturing goods for export. Now that all of the manufacturing has moved to China; these industrial buildings are slowly being turned into other uses such as offices.
The Industrial Properties offer an interesting investment as they are exempt from the government legislations enacted in 2010 whereby a special stamp duty is levied if you buy and sell a property within 2 years. Moreover, there is limited supply and demand is forever growing.
I found a site recently that specialises in Industrial Properties in Hong Kong (www.oneday.hk). For residential properties you can use www.gohome.com.hk and Square Foot (www.squarefoot.com.hk).