There are multiple reasons for the price of homes to soar but to blame it solely on one issue such as the Places to Grow legislation is misleading.   Part of the issue is demand.  The GTA  population has grown by over 100,000 people annually for more than a decade.   If the GTA (or Vancouver) wasn't an attractive place to live there wouldn't be growth.   Demand will continue to grow. 

Interest rates are another key reason for soaring prices.   Low rates have allowed borrowers to take on larger mortgages.   Bottom line, buyers are bidding up house prices because they qualify for the loan.  

Finally, yes, there is a "land" supply challenge.  There aren't many vacant lots on which to build detached homes within the GTA.  Further, more car dependent sprawl is not the answer.  Creative options to allow for increased density of the inner burbs with more single family homes are needed.