Construction started on 2,607 new homes in September, an 18% increase on the number in the same month last year.
However, the number of commencement notices lodged was down slightly on the previous month, when work began on 2,770 new houses or apartments.
It means that building work has begun on 23,923 new homes since the start of the year.
That represents an increase of 14.3% on the first nine months of last year when 20,919 units were commenced.
During September commencement notices were lodged for 445 new homes in South Dublin County, with 291 in Dublin City and 200 in Cork City.
The smallest number of notices received by the Building Control Management Service during the month was in Leitrim and in Sligo, where just three each were lodged.
