The agency says higher monthly prices in eight metropolitan areas offset lower prices in seven areas.
It says the St. Catharines–Niagara and London areas posted the largest monthly price gains. Prices were also up in Hamilton, Kitchener–Cambridge–Waterloo and Calgary.
Statistics Canada says prices for new homes were down in Ottawa–Gatineau, Vancouver, the combined metropolitan region of Toronto and Oshawa, Charlottetown, Halifax, Saskatoon and the combined region of Saint John, Fredericton and Moncton.
Prices were unchanged in six of the 21 metropolitan areas surveyed.
The index for July was up 1.4 per cent compared with a year ago, the smallest annual increase since December 2013.