An interesting measure is to cross-correlate the Teranet HPI to single family detached permits, producing an RSQ of 0.94. Although it's not obvious in the graph, the HPI will slightly lead the change in building permits. If the HPI rose/dropped that means building permits were likely to rise/drop in about 1-2 months:
There is more supply on the horizon, though single family permits have waned of late. Somewhat strange is the marked increase in the value per permit of 1+2 dwelling constructions, that have doubled in the past four years. If I were to guess I would say this is due to how dwelling costs are reported and the mix of dwellings, more than an increase in construction costs.