COEUR d’ALENE — After a tense Monday night meeting where Kootenai County commissioners debated the scope and cost of the ongoing Justice Building expansion, the board voted unanimously Tuesday to approve the project’s second phase.

This phase of construction will cost $8.4 million, covered by American Rescue Plan Act funds set aside last year for the expansion. It will involve building structure, detention doors, frames and hardware, detention glazing, elevators and mechanical and electrical.

The county broke ground in September on the 60,000-square-foot expansion to the Justice Building, which will add three courtrooms and facilities for the Sheriff’s Office, district court employees, prosecutors and other county staff.

The expansion is estimated to cost $38.3 million in total, about $10 million of which be covered by county funds. Commissioners Bill Brooks and Bruce Mattare have balked at the cost, with Mattare calling for Monday’s special meeting to discuss how the county will pay for the project.

After criticizing the price tag and a planning process that he said left taxpayers out of the loop, Mattare said Tuesday morning that he’ll defer to Commissioner Leslie Duncan’s judgement because she has been more intimately engaged with the Justice Building expansion than he has.

“I’m going to rely upon your judgement that we have the money, that it makes sense to build this fourth floor and at this point, like I said, I think we’re on for the ride,” Mattare said.

He elaborated Tuesday afternoon during the board’s regular business meeting.

“In the end, I just have to defer to you because I don’t have that benefit of talking with different people, making sure the issue is correct, especially with a building like this, because the biggest challenge for me is I don’t know what I don’t know about construction,” Mattare said to Duncan. “As a member of this board, I don’t know what questions to ask to keep us out of hot water and the only way I get that remote possibility is if I have a go-to person who knows what is going on.”

Duncan said she takes it upon herself to seek the information she needs in order to make decisions.

“I don’t wait until somebody presents it to me,” she said. “I go after it. I have for five years.”

Brooks said Tuesday that scrapping plans for the building’s fourth floor, which is meant to house the Kootenai County Prosecutor’s Office, would be a “quick and dirty” way of cutting costs but a bad idea in the long run. Removing the floor could save $3.8 million but incur additional costs associated with redesigning the building.

“Why do we have a fourth floor to begin with?” Brooks said. “We did it because we needed it. I think managing the costs are more important.”