It seems to me that the bank economists have issued a timely warning. Across Canada, most housing markets currently are not overvalued: houses in these regions are still more affordable than historical averages  based on measures of affordability that use discounted (vs. posted) mortgage rates (e..g Bank of Canada housing index). Toronto and Vancouver have been less affordable than their historical averages for some time, but it is only recently that price increases in these two cities have pulled the national average above the historical norm for affordability.