Vancouver doesn't have the same anti-development issues that SF has, and has been building multi-unit condos and apartments all over the region for decades. Multi-unit housing starts are about at its highest level ever. The average price of a detached house however is C$1.3 million (~US$998k thanks to the weak Canadian dollar) and rising. Low interest rates, "fear of missing out," incredible amounts of real estate speculation and a dash of foreign investment can go a long way.
It's likely that the strongest benefits to increased supply in SF will manifest itself in lower rents and/or lower rate of rent increases.