It follows huge spending on a bike shelter outside Leinster House and a security hut outside the Department of Finance.
The Office of Public Works is under the spotlight again, this time over a wall.
It's emerged it spent almost half a million euro replacing a 70 metre wall outside the Workplace Relations Commission in Dublin.
That's double the estimated cost and follows on from the infamous bike shelter outside Leinster House.
Public procurement expert Paul Davis from DCU says the OPW underestimated the cost.
"Halfway through, they discovered that they actually had a live electricity line," he said.
"You would have assumed that somebody who was looking at a demolition and construction would have seen that beforehand, and therefore built that into the tender costs; they didn't.
"And so they got caught; and getting caught means then after the fact of what the original tender was, they had to go out and actually get additional works done for," he added.
