Animaflora via Getty Images

Soaring rents are no longer just a Toronto and Vancouver problem. The latest survey from rental site Padmapper shows rents jumped by double digits over the past year in 17 of 24 Canadian cities, with some of the country's (previously) most affordable markets seeing the largest hikes. Toronto retained its position as the country's most expensive rental market for one-bedroom units in December, with asking rents rising 11.9 per cent in a year, to a median of $2,260. Two-bedroom rents rose 13.1 per cent, to $2,850 per month.

Padmapper/HuffPost Canada One-bedroom rents.

By comparison, Vancouver had a tame year, with one-bedroom rents up 6.5 per cent, to $2,130, while two-bedroom units rose 0.9 per cent, to $3,230. Meanwhile, many smaller and mid-sized Canadian cities saw considerably faster rent jumps, with hikes in the 15-per-cent range in Halifax, Kingston, Kelowna, London, St. Catharines and Victoria. Quebec's two largest metros, Montreal and Quebec City, also saw rent hikes in this range.

Padmapper/HuffPost Canada Change in rental rates.

So why are rental rates rising in many cities that haven't seen a house price boom? What explains, for instance, struggling Saskatoon's 10.7-per-cent rate hike? The likeliest culprit is the mortgage "stress test" put into place at the start of last year, combined with rising interest rates that have pushed up monthly mortgage payments. While the stress test and the Bank of Canada's rate hikes were meant in part to keep Canadian homebuyers from overextending themselves on their mortgages (and the evidence so far suggests it has worked), it may have had an unintended consequence: Forcing would-be homebuyers to stay in rental housing longer as they save up a larger down payment. Watch: GTA renters are considering moving out due to high housing costs. Story continues below.

According to recent estimates from economists at Royal Bank of Canada, the stress test significantly impacted home affordability in many Canadian cities, including those that hadn't seen rapid house price growth in recent years. In Halifax, for instance, the qualifying income needed to buy an average home jumped to $70,000 from $52,000 in the past three years, with much of that due to the stress test and rising interest rates.