The Australian Industry (Ai) Group has released September's Performance of Construction Index (PCI) for public viewing, with engineering construction continuing to grow despite a deceleration.

Big public works like the Sydney Metro are driving growth in construction engineering.

The Australian PCI, released in conjunction with the Housing Industry Association (HIA), tracked its eighth month of expansion across the Australian construction industry. The index pulls together and weights various metrics across the construction industry, with measurements above 50 indicating expansion.

Engineering construction managed to maintain at 56.9 points, declining from 58 in August. The overall index fell 0.6 points to 54.7, remaining above the 12-month average of 52.2.

Engineering construction and house building remain the big drivers of the industry, with apartment building a significant drag. Both engineering and housing sectors are solidly in growth phases and well above 12-month averages.

Employment and wages also had a strong month, with growth in wages at their highest level in almost nine-and-a-half years. The PCI attributes this to increased investment in transport infrastructure and other public works driving demand for skilled labour.

However, a deceleration in new orders (down 4.2 points to 53.3) may suggest a slowdown in activity in the coming months.

Elsewhere, commercial construction remained flat at 50.3 (up 0.1); house building maintained speed at 56.6 (up 0.1); and capacity utilisation stayed stable at 77%. Meanwhile, significant contraction in the apartment sector, down 3.3 points to 41.1, makes it the construction industry's only sector in negative growth (and by far its worst performer).