CMHC says the equivalent of 180,560 units were started on a seasonally adjusted basis last month, down from 193,199 in November.
CMHC says the number of multiple-unit starts in urban areas fell to 103,054 units in December from 110,766 in November.
There was also a decline in urban single-family house construction, which fell to 59,861 units from 62,861.
On a regional basis, there were small increases in Ontario and B.C. urban starts and relatively large declines in other parts of the country.
CMHC said the six-month trend in December was 192,047 units, down from 194,807 in November.
In a separate report, Statistics Canada reported Friday that the value of building permits dropped by 13.8 per cent from October to November, when they had a total value of nearly $6.59 billion.