All of Vancouver between Fraser and Boundary, the Fraser River and 49th should be turned into Montreal-style three storey flats, with pockets of ground floor commercial strips every 6 blocks or so. Vancouver could house an additional 3 million people in this scenario.
As of right zoning would require 25% of units be available to first time homeowners making under $75k, available with low down payments so long as these people cannot rent out or resell their discounted flats for a number of years, I'd suggest 15-25 is fair. These folks would get discounts in the form of low or no income tax for 10 years, thus ensuring working adults inhabit these units.
Possibly the affordable homes would be built above the CRU "villages" both on high streets and corner lots.
I'd suggest a strict high quality, localized architectural aesthetic be maintained throughout the area. Eg. similar to this excellent TH/flats development in Esquimalt
https://imgur.com/a/R1PrdFK