Construction fell 0.9 per cent from July, after a surprise 2.1 per cent bounce the month previously.
The main drag came from new work, which fell by 15.6 per cent. Repair and maintenance work declined by 4.2 per cent.
Over the same period, new infrastructure construction fell by 18.4 per cent, while work on new public housing fell 20.7 per cent.
A steep slump in construction output was the main drag on Britain's economy in the first half of 2012, pushing the country back into recession.