The Australian Industry Group (AiG) released its construction data for Australia on late Tuesday evening. The Ai Group/HIA Australian Performance of Construction Index fell to 51.9 in September from 53.8 in August.
A reading above 50 indicates expansion in the sector.
The decline was driven by a drop in engineering, which slid by 9.3 point to 36.6 in September.
"Residential construction activity remains the cornerstone of the broader construction industry and will retain this role into at least the first half of 2016," HIA economist, Diwa Hopkins, said.