The Public Accounts Committee (PAC) has heard the expected cost of the renovation of Leinster House has more than doubled to €17m.
This week's sighting - and later capture - in the Dail bar of a rat was also on the PAC agenda yesterday.
Peter Finnegan, the secretary general of the Houses of the Oireachtas Service, defended the costs of refurbishing the 18th century building, insisting it represented "outstanding value for money".
Fine Gael's Alan Farrell jokingly suggested that ratatouille could be put on the canteen menu, but also added more seriously that pest control is a concern for people working in Leinster House.
"It's not a question. It's just a very badly performed pun on my part," the TD said.
Independent TD Catherine Connolly said she takes comfort from the fact the rats haven't deserted Leinster House, adding: "This ship isn't sinking yet, so it looks like we might be back and there's no election looming."
The Dail bars - both the exclusive Members' Only Bar and the adjoining one for the public - remained closed yesterday.
That was after Fianna Fail leader Micheal Martin spotted the rat on Tuesday afternoon.
Pest control experts were later called in to Leinster House after staff failed to take down the rodent with a golf club.
The rat was caught on Wednesday evening.
An Oireachtas spokesperson did not say when the bars will re-opened, and a statement said they "are still closed until further notice".
Separately, Mr Finnegan told TDs that "essential restoration and structural works" on Leinster House are almost complete with the handover from the Office of Public Works - which has been managing the project - due to take place on August 2.
Sinn Fein TD David Cullinane asked about original estimates for the cost, which were put at €8m in 2017.
Mr Finnegan said this had been "quite a rough estimate".
Mr Cullinane said: "It would be better if we didn't have rough estimates. Once figures are put out like that, the problem is then that if it costs more we're into the overspend territory."
Mr Finnegan confirmed the cost is now set to be around €17m. He said reasons for the overspend included the need for additional fireproofing, and requirements for some of the work was not known before the contractors arrived on site.
Mr Finnegan said that while extensive surveying was carried out beforehand, "it's impossible to catch everything as part of that process".
Later, Fianna Fail's Shane Cassells asked Mr Finnegan if he feels the €17m spend represents value for money.
Mr Finnegan said he does, and added that he has walked the site on many occasions and seen the "enormous amount of work involved", from electricians to stone masons.
"That building was erected, built, constructed in 1745. We're coming up to the 275th anniversary next year," he said.
"To spend €17m - which has been the only major capital expenditure on that building on restoration - if you average that out over 275 years, it's outstanding value for money.
"One of the really nice things about this project is there will be a building for the people of Ireland at the end of it.
"We want people to come in and see the building because the work is to an extremely high standard and, ultimately, it's the people's parliament."