DreamPictures via Getty Images Home affordability has become so strained in Canada's priciest markets that if incomes don't catch up, house prices will fall, says the co-author of National Bank of Canada's latest home affordability report.

Home affordability has become so strained in Canada's priciest markets that if incomes don't catch up, house prices will fall, says the co-author of National Bank of Canada's latest home affordability report. The data for the third quarter of this year show the costs of owning a home rose in nine out of the 10 major cities surveyed, with only Winnipeg showing a minor improvement. Affordability has been deteriorating steadily for more than three years at this point. Watch: You can buy a burned-out house in Vancouver for $4 million (story continues below)

Softer prices in Toronto and Vancouver didn't help with home ownership costs, because mortgage rates are on the rise and wages in those cities slid during the quarter, economists Kyle Dahms and Matthieu Arseneau wrote in the report. In both Toronto and Vancouver, affordability is at its worst levels since around 1990. Back then, the Bank of Canada pushed interest rates to double digits, far higher than they are today, making mortgages supremely unaffordable.

HuffPost Canada Owned Home affordability is at its worst levels since the early 1990s in Toronto and Vancouver.

But the worst deterioration this quarter took place in Montreal and Ottawa, where it was rising prices, on top of rising mortgage rates, that took a bite out of affordability. Prices in Ottawa rose at a 10-per-cent annualized rate in the third quarter, while Montreal — which is now eyeing a foreign buyers tax along the lines of those in B.C. and Ontario — saw prices rise at an 8-per-cent clip. "These markets appear to be unaffected by rising interest rates and tighter credit standards as shown by ... market conditions being strongly tilted in favor of sellers," the National Bank economists wrote. Their quarterly report looks at house prices in 10 cities: Calgary, Edmonton, Hamilton, Montreal, Ottawa, Quebec City, Toronto and Winnipeg. No cities in Atlantic Canada are included in the survey. Earlier on HuffPost Canada: Vancouver Luxury Housing Market Drops From World's Hottest To Dead Last

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'Recycled' Listings Mean Canada's Housing Market Data May Not Be Reliable All the same, Montreal and Ottawa remain among Canada's more affordable major cities. A mortgage payment on an average home eats up 32.7 per cent of household income in Montreal and 28.7 per cent in Ottawa. Compare that to 68.2 per cent of income in Toronto, and 80.8 per cent of income in Vancouver. Vancouver's detached homes just for the 1% now The National Bank's report shows that Vancouver real estate prices have risen to the point that you would need a household income of $238,818 to qualify for a conventional mortgage (20 per cent down) on a detached home. That's just slightly less than the income you need to be in Vancouver's one-per-cent club: $246,000 a year, according to data from the 2016 census. In Toronto, you need a total income of $159,289, while in Quebec City, the most affordable major market, you can get a single-family home on $51,000 a year.

HuffPost Canada Owned Vancouver's real estate requires far more income to buy than any other Canadian market.