Growth in Ireland's construction sector picked up in December according to the latest Ulster Bank purchasing managers' index.
The main index rose to 58.6 - up from 55.5 in November. Any value over 50 indicates growth.
Activity in Ireland's construction sector has now increased in each of the past 28 months - December's figures were the strongest since July.
There has been a spike in new orders, and the rate of job growth also increased.
Ulster Bank's chief economist Simon Barry says that the sector ended 2015 "on a firm footing."
"Overall activity trends were buoyed by a strong acceleration in both commercial and housing activity, with the pick-up in the residential arena a particularly welcome development given concerns about the housing supply shortfall.
"Growth in civil engineering continues to lag some way behind the other sectors though it did record a fourth consecutive month of expansion last month," Mr Barry added.
Optimism also remained strong in the sector at the beginning of 2016.