well, you're totally wrong about the cause of the housing bubble, but correct about a contributing factor. the reason that there's a housing bubble is because of low interest rates have spurred unprecedented borrowing by canadians (and foreigners borrowing against hong kong-held capital or assets) to enter the housing market. so many people are doing this at once that prices are rising very rapidly. your solution of converting low rise neighborhoods to mid rise neighborhoods would help at the margins, but only so much. the massive price gains being seen in vancouver and toronto are almost all accounted for by the value of single family homes. condos are flat or up just a little, year over year. so, your idea to remove detached homes from the board and move them into the condo market assumes a lack of housing writ large, not a lack of a specific class of housing. you back into being correct by saying that if developers could get their hands on detached housing, they could build more units, that's right, but because it would simply decrease the number of single family homes that could be bid up. why? well, the great secret to white and asians who can't read mandarin/don't know about real estate is that there's a shadow market that operates in hk/mainland china that basically treats single family homes in some canadian neighborhoods as pure speculation markets, like stocks. if you disrupt this market by rezoning for height, you could scare enough people out of the market to radically lower prices, though they'd still make out well. BUT the larger point is that the "bubble" is in one class of housing. toronto and vancouver developers are doing a great job responding to insatiable demand among canadians and small time investors looking to get into the condo market in high rise. that's not what's driving these massive spikes in price. so your theory about zoning for midrise, i agree with it completely (actually, i'm thinking wall to wall 10-15 stories) but it's not why you're seeing these numbers.