The agency says the increase was largely the result of higher new home prices in the Prairie region.
The Calgary area, where prices rose 0.8 per cent, recorded the largest monthly price advance among the municipalities covered by the survey.
The combined region of Sudbury and Thunder Bay posted a price advance of 0.5 per cent in May.
New housing prices were down for the third consecutive month in Ottawa–Gatineau and Vancouver.
Prices were unchanged in seven of the 21 metropolitan areas surveyed.