Home ownership became less affordable during the first quarter, especially in Vancouver where it took nearly three-quarters of family income to pay for mortgages, property taxes and utilities, according to an RBC Economics report.

RBC said that while a detached bungalow in Vancouver ate up an average 72.1 per cent of income, up 3.4 percentage points, while costs in other major Canadian cities were also on the rise.

In Toronto, housing expenses ate up an average of 47.5 per cent of income (up 0.8 of a percentage point), while in Montreal it was 43.1 per cent (up two percentage points), and Calgary devoured 35.9 per cent of income (up 0.9 of a percentage point).

Other key cities like Ottawa expenses took 39 per cent of income (up 0.4 of a percentage point) and in Edmonton it was 31.5 per cent (up 0.5 of a percentage point).

The bank's affordability scale, which measures the proportion of pre-tax household income needed to pay mortgages, finds that all three major housing types were less affordable in the first quarter.

The amount of income taken up by housing costs on a detached bungalow rose 0.7 of a percentage point to 40.5 per cent. The figures for a standard two-storey home and a condominium both rose 0.2 of a percentage point to 46.2 and 27.7 per cent, respectively.

The association said national sales activity in each of the first three months of 2011 ran close to five- and 10-year monthly averages. However, home prices were up about eight per cent from the year earlier.

That followed an easing of the burden in the second half of 2010, largely due to falling long-term mortgage rates.

Home ownership costs could continue to rise as the Bank of Canada is expected to soon resume raising short-term interest rates, but expected growth in household incomes will likely soften the blow, said senior economist Robert Hogue.

"Interest rates will likely soon start to rise again, leading to a period of steady increases in homeownership costs. This, in turn, will contribute to a flattening in Canadian housing demand going forward," said Hogue.

"We could experience some turbulence this spring and summer, given that new tighter mortgage lending rules in March and April likely shifted home buying activity to earlier in the year."

Home owners in British Columbia, where sales of multi-million dollar homes are surging, particularly in Vancouver. Quebecers also saw noticeable rises in home ownership costs.

The picture was mixed in other parts of the country, with Ontario, Alberta and Saskatchewan seeing ups and downs, depending on the housing type.

"Despite the latest erosion in affordability, provincial levels generally continue to stand near their long-term averages, suggesting that owning a home remains affordable or, at worst, slightly unaffordable across Canada — with Vancouver being a notable exception," Hogue said.