On the supply side, a manufacturer of an item will typically make as many items as he can get away with selling at a profitable price. As prices rise, assuming his costs are the same, his motivation is to manufacter even more items to sell them at even higher profits. If he perceives demand to be strong and that there are willing buyers at ever higher prices, then he will continue manufacturing the item in ever increasing quantities and prices. This usually results in all current demand being used up and then the manufacturer must focus on creating demand for his product through creative marketing and by affecting the conditions in which his item can be used. Sometimes this results in a paradigm shift in social perception or some totally new use for a product never imagined before (think computers before and after the advent of the internet). Sometimes it ends badly for the manufacturer as he creates too many items than can possibly be sold with any level of demand and he is motivated to either sit on a large quantity of items or sell them at whatever price he can get.
Throughout history, there have been many situations where manufacturers make too many items, perceiving demand to be higher than is actually is, and there ends up being a glut on the market. This glut is fantastic for potential buyers, many of whom were priced out of the market for the item as prices rose faster than they could save for the item. The glut is horrible for those who bought the item at a much higher price. They are often left bitter and resentful of the new buyers buying the item at a much lower price.
So, the question for today is, will there be a housing supply glut in the Vancouver area in the next couple years? If I were a housing manufacturer in Vancouver, I would be eager to sell as many of my items as possible at today's prices given the profit involved. Why not manufacture more if the demand seems to be there?