SPRINGFIELD — It’s been about four years since construction crews began ripping through the north end of the 19th-century Illinois Capitol, the historic building’s latest modernization, which will include updated offices and enhanced security, as well as a refurbished Senate chamber finished last year.

The $350 million project, the second major overhaul of the Capitol in just over a decade, is about seven or eight months from completion, according to Andrea Aggertt, the Capitol architect overseeing the work. The renovation encompasses the building’s north wing, a new underground conference center and parking garage, extensive structural upgrades and a reimagined main entrance for visitors.

It was originally expected to wrap up last year. But delays — many tied to harsh winter conditions — have slowed progress.

“Mother Nature has not been kind to us recently,” Aggertt said during an interview with the Tribune in mid-December on a cold, gray, windy day on the construction site, as it was covered in mud with sprinkles of leftover snow. “We’ve had people get stuck. Difficulty in getting material back to the building. The cold weather, it slows work down outside and also on the inside.”

Springfield endured an unusually snowy start to winter. About 19 inches of snow have fallen over the capital city so far this winter, the third-highest total for the area in over 50 years, according to Rebekka Copple, a meteorologist for the National Weather Service in downstate Lincoln.

“The last two years, we poured concrete all the way up until the middle of January,” Aggertt said at the construction site on Dec. 18, “and we haven’t poured concrete since it started snowing in November.”

But the weather hasn’t been the only obstacle. For instance, Aggertt said in a separate interview in March that the parking garage had been a few months behind schedule since workers did not install rebar in an area, requiring supplemental brackets. The fix didn’t add to the overall cost, but it did add time to the project.

Crews also encountered unsuitable soil beneath the garage and uncovered aging structural elements inside the Capitol that required remediation, she said.

“Sometimes we run into rooms or spaces that once we demo it, it is a complete surprise,” Aggertt said in December, clad in an orange and neon-green-and-silver-striped protective vest and wearing a black hard hat. “We have made decisions best for the building and financially smart decisions, but sometimes that means we sacrifice in schedule.”

The most visible change on the Capitol’s north side will be a two-level visitor welcome center that will become the building’s new main entrance. Before construction, the site served as a circular driveway used by lawmakers and staff.

The north entrance also carries heavy historical weight. In 2004, a gunman fatally shot an unarmed security guard stationed there, prompting the installation of metal detectors and armed security throughout the Capitol.

Aggertt declined to detail specific security features planned for the new center but said it will include two screening queues, each accommodating about 75 people, along with an information desk to help visitors locate their legislators.

A short retaining wall is being built on the north end to prevent vehicles from driving onto the lawn, according to Aggertt. Workers have also designated a dedicated drop-off lane on Monroe Street, with room for about five or six buses carrying rally or school groups descending on the Capitol. Above the welcome center entrance, a plaza with a winding walkway will serve as a gathering space for constituents and students, she said.

The renovation also aims to significantly improve accessibility throughout the building, including restrooms, doorways and hardware, Aggertt said.

In 2022, then-Senate Republican leader Dan McConchie, who uses a wheelchair, told the Tribune about how many Senate offices had limited accessibility, and when he started working in the chamber several years earlier he had limited choices for office space.

“There was only I think three out of over 20 offices that actually met accessibility standards,” McConchie, who left the Senate last year, recalled at the time. “So, I was limited in the number in which offices I could choose because, you know, most of them … either the doors weren’t wide or other things. So, yeah, there’s a whole bunch of issues. I mean, this typically happens with a very old building like that.”

A spokesperson for Aggertt provided a breakdown of the costs for the project, including $243.5 million for the north wing of the Capitol building, $14.5 million in change orders, $46.6 million for the parking garage, including the site preparations, and $10.5 million for early construction, which included basement demolition and the rerouting of utilities.

The spokesperson also said $2.3 million was set aside for the renovations to two office buildings near the Capitol — the Michael J. Howlett and William G. Stratton buildings — as well as various equipment purchases and design fees. Senators convened in the Howlett building during renovation of the Senate chamber inside the Capitol.

While Aggertt said work is on track to be completed under budget, the north end’s $350 million price tag dwarfs the $51.5 million price tag on the Capitol’s west wing renovation in the early 2010s.

That earlier project drew criticism over details, such as copper-clad wooden doors that cost nearly $670,000, with then-Gov. Pat Quinn complaining, “We don’t need to have the Palace of Versailles as our state Capitol.”

Much of the current expense, Aggertt said, stems from deterioration that wasn’t fully understood before construction began. The Capitol opened in 1888 after 20 years of construction and originally cost about $4.5 million.

“We found structural elements we had no idea that were there,” Aggertt said. “We had found walls that weren’t really supported very well, so we had to take the entire load-bearing masonry wall down, build it all back up and put in new structure because we want to make sure whatever we’re building has no ramifications in the next 100 years, when people well beyond us are in the building.”

The Tribune was not permitted to tour the interior office spaces under renovation, which remain sealed off. Before construction, some of those areas were tucked into cramped mezzanines added in the 1960s and ’70s with lowered ceiling heights.

One completed north end interior space is the Senate chamber, which reopened in January 2025 after three years of work.

As crews opened walls in the north wing, they also uncovered relics from earlier eras, including business cards and a 1938 letter documenting an issue between the state auditor and treasurer.

Outside, the site remains fenced off. Temporary air ducts protrude from windows to ventilate spaces under construction in the Capitol. Slabs of stone that were salvaged from the building — including massive “cheek walls” that once framed the north entrance steps — sit stacked nearby, awaiting reinstallation.

“You can’t just take a forklift and have somebody yank it off the building really quick and put it in storage,” Aggertt said. “It takes care, because those are the things we’re salvaging to make sure we put it back on the building.”

“We’re storing anything that we had determined we wanted to use and anything that maybe if we didn’t want to use it, we wanted to save it just in case we needed it ever again on the building,” Aggertt said, “because getting material is extremely hard to replicate when we have material from the late 1800s.”