It's getting a easier to afford a home in Calgary and Regina, but housing is moving out of reach for many buyers in Toronto and Vancouver, according to research by RBC Economics.

The rate cut announced by the Bank of Canada in January helped make housing more affordable in most of Canada, because mortgage costs fell, according to RBC's March report on housing trends and affordability.

Higher home prices in Ontario and some parts of British Columbia meant the average affordability level across the country deteriorated, RBC said.

It notes the sharp contrast between these hot housing markets, and the story in the oil-producing provinces.

Calgary house sales plunge

Calgary’s affordability improved as lower oil prices started to have an effect, in the form of fewer sales and more homes on the market.

House sales fell by 35 per cent in Calgary in December 2014 and January 2015, and there was a wave of new listings, but that has yet to translate into lower prices, RBC said. That situation may not last long, as RBC analysts say they're already seeing prices for bungalows drop and other segments of the market may not be far behind.

Market confidence gave in to a wave of cutbacks announced by the oil industry... - RBC report

"After showing impressive resilience in the face of plunging oil prices since last summer, market confidence gave in to a wave of cutbacks announced by the oil industry and collapsed as the winter rolled in," its report said.

Saskatchewan home resales also fell by 4.6 per cent in the fourth quarter and 19 per cent in January, reflecting the impact of decreased oil revenue. Average prices were down by 0.6 percentage points for bungalows and two-storey homes, though there is still is strong demand for condos.

RBC said it's a buyer's market now in Saskatchewan, especially in Regina and Saskatoon, where prices had been "under downward pressure even prior to the fourth quarter."

Atlantic Canada most affordable

Affordability improved in Manitoba, Quebec and Atlantic Canada, which has long had among the most affordable housing in the country.

Vancouver, by contrast, is the least affordable market and that didn’t improve in the final quarter of 2014. House resales were at a four-year high, but there was little new supply on the market, heating up home prices.

Toronto saw robust demand that drove up prices, though gains among condo resales were much lower, RBC said.

"This contributed to raise the ownership bar ever higher and further deterioration in affordability," its report said.