The State Office Building project includes replacing old air handling systems that haven’t been fixed since the the building was last renovated in the 1980s. (Glen Stubbe, Star Tribune/The Minnesota Star Tribune)

Near the State Capitol in St. Paul, construction fencing went up while some trees and light posts came down last week, the first visible signs of major changes coming to the nearly 120-year-old government campus.

The biggest — and most controversial — of those projects is the $454 million renovation of a 1932 building adjacent to the Capitol used for state and legislative offices. State Republicans are trying to halt the project even as work begins.

Less discussed is the soon-to-be demolished former Ford Motor Co. assembly plant near the Capitol, as well as the potential demolition of another office building in the near future. While plans are being finalized, both could make way for more green space and better accessibility for the public.

The entire work will produce a Capitol complex that's better integrated into the neighborhood and "grounds that are actually approachable by the public, by the community," said Curt Yoakum, spokesman for the state Department of Administration. "Now you have a Capitol complex that is almost an island on itself."

The changes follow the $310 million, four-year renovation of the Capitol itself. That project meant a massive reshuffling of government offices until the building reopened in 2017. Similar disruptions are ahead, though not on the same scale. The work is scheduled to wrap up in 2026.

The Secretary of State's staff moved out of the State Office Building this month as construction crews closed down the north entrance to the building and a tunnel connecting the offices to the Capitol. The Secretary of State's office will temporarily relocate to the Veterans Services Building nearby.

House members will continue to use their offices and hearing rooms in the building through the 2024 session. After session adjourns, they'll move to the Centennial Office Building for the duration of the project.

Both parties agree some fixes are long overdue in the State Office Building. It suffers from mold and major security vulnerabilities that are on the radar of the State Patrol. Pipes have burst several times and spilled water into the building, as recently as this month, Yoakum said. The building's footprint will also be expanded to add hearing rooms and make the space more accessible to the public.

Republicans continue to raise concerns about the cost, which is more than the entire Capitol renovation and a new office building for state senators that opened in 2016.

"I don't disagree that there is need to update the HVAC system and technology and a few things," Rep. Kristin Robbins, R-Maple Grove, said after offering a motion to stop the project at a recent House Rules committee meeting. "But the scope and scale of this project ... is unconscionable."

Democrats rejected that motion as out of order, and the state says delays could make the project more costly.

"If you make changes during construction, whatever that may be, those are generally more expensive and costly to do, and sometimes you're too far down the road to make any substantial changes," said Wayne Waslaski, an assistant commissioner at the Department of Administration.

He said the size of the investment should be considered in terms of an "80- to a 100-year life" of the building. "This is going to serve the public for many generations to come."

Not long after legislators return to their renovated offices in 2027, their temporary space in the Centennial Office Building could be torn down. The Department of Administration has submitted a proposal to the Legislature to explore demolishing the building. Constructed in 1958, it has much of the same wear-and-tear issues as the State Office Building but is less central to the Capitol campus.

Getting rid of that building, as well as the old Ford plant, would dramatically change the area surrounding the Capitol. The Ford building demolition, which will make way for new green space, is expected to start in January and last about six weeks.

Built in 1914, the former car plant at 117 W. University Ave. housed several businesses and a state bookstore after closing down nearly a century ago. It has been vacant since 2004 and fallen into such disrepair that it's a safety hazard.

The Capitol Area Architectural and Planning Board is also working on a design framework that will look at the roads coming in and out of the Capitol campus.