JE Dunn Construction Restores Historic Fabric While Updating Building Systems in Wyoming State Capitol
Extensive Investigative Work and Old-School Construction: 107 Trade Partners and 2,500 Workers Complete $300M Wyoming Capitol Square Project with JE Dunn Construction
What does it take to restore 1880s grandeur to a National Historic Landmark, while simultaneously incorporating modern building systems and extra spaces?
For the $300 million Wyoming Capitol Square project in Cheyenne, Wyoming, it took 2,500 people and 107 trade partners – not including vendors and second-tier partners – working with JE Dunn Construction of Denver, Colorado, the project’s construction manager, through almost five years of investigative and construction work.
The project centered around the rehabilitation and restoration of the 129,539-square-foot Wyoming State Capitol, built in 1886. The invasive work required to replace outdated building systems, add life safety infrastructure, and increase public and meeting room space created the opportunity to restore many historic features. That included original paint colors and themes, ceiling heights, and hand-carved details.
“We brought in cooling for the first time, as well as efficient heating and new life safety systems,” said Matt Betts, JE Dunn’s Senior Project Manager. “Our guiding principles were restoring the architecture, but also making it a safe place for people to convene and interact with their government.”
Approximately half of the project’s construction budget covered work on the Capitol building. Crews also remodeled and expanded the below-grade connector between the Capitol and the Herschler office building; renovated and expanded the Herschler Building; built a 15,395-square-foot central utility plant to replace the old one; and added site improvements. At the peak of construction, almost 375 people worked onsite at one time.
Investigative work for the project began in November 2014. Capitol building occupants relocated and the building closed in December 2015 when the team undertook their heaviest investigative work. Construction officially started in August 2016, and the project finished on schedule for a July 10 grand opening attended by several thousand people to celebrate the 129th anniversary of Wyoming’s statehood.
Finding What Hides Underneath
Wyoming’s legislature began saving money for the project in 2003, including reversions from other state construction projects and direct appropriations. In 2014, the legislature authorized funding and approved the scope of the project, with HDR, Inc., of Denver as Architect of Record.
Through a best-value process, the state selected JE Dunn in July 2014. From that point, “We worked hand-in-hand with the owners and design team, then executed a Guaranteed Maximum Price contract in August 2016 as Construction Manager at Risk,” Betts said.
Extensive investigative work verified the existing structure and architecture, including elements hidden behind previous renovations. “By the time we started construction, our crews had already been onsite for over a year-and-a-half,” Betts said.
That included JE Dunn’s subcontractors. “We brought on a lot of our key restoration trade partners early in design to help identify the scope, as well as the means and methods, schedule, and costing,” Betts said.
Much of the work, in fact, was done by hand. Because of the early trade partner involvement, all of that was built into the budget and schedule. The team’s selective interior demolition at the Capitol revealed original paint colors, as well as hidden crown moldings, coffered ceilings, and arches. The team reused as many original pieces as possible, including tile, metal, and trim.
A few unknowns still existed when construction began. For instance, “In a couple of areas where the Herschler Building and the Capitol connect, we didn’t have as-builts,” Betts said. “We worked carefully with the ownership team and the architect to provide responsible allowances for unforeseen conditions like that where we knew there would be exposure and risk. We also started demolition in those areas as early as possible so we could react and mitigate those risks to keep the project on time and within the budget.”
Despite extensive investigative work, JE Dunn’s team still found a few surprises in the Capitol building. For instance, “We opened up a wall during demolition and found an original door that had been plastered over,” Betts said. “That allowed the architect to model new door hardware off the original hardware.”
Crews also unearthed opera posters from the 1880s. “We believe they were posted on fences, then some of the wood from those fences was used in the original floor structure,” Betts said.
600 Micropiles and Buried MEP
The soil under the Capitol wasn’t an unknown – just not good news. “The geotechnical report indicated poor soil density,” said Steve Fore, JE Dunn’s Project Superintendent. “It wasn’t compact enough and the building had settled over the years, so the design team elected to go with a micropile system to stabilize the whole structure.”
The underpinning process for the micropiles strengthened the Capitol’s existing foundations to bear heavier loads than originally designed for in the late 1880s and allowed new utilities to pass under the historic footings.
To install the new foundation support system, crews drilled micropiles into the ground close to the wall, one inside the building and one outside, then connected them with a steel needle beam through trenches dug under the existing foundation.
“There are over 600 micropiles ranging from 27 to 33 feet,” Fore said. “They were done with a 51-millimeter screw and simultaneously grouted while they drilled. After those set for four to seven days and tested at the right poundage, then we could load them.”
JE Dunn’s team excavated 3 to 6 feet below the slab on grade to install the new structural components and MEP systems. That work required collaboration among many trade partners.
“We laser-scanned the entire facility, then overlaid the existing structure with the new micropiles and underpinning,” Betts said. “We did a lot of coordination not just with MEP trades, but structural trades as well.”
Above-ground MEP work presented its own challenges. In order to install new mechanical chases, “We had to take out shear walls, so we worked hand-in-hand with our trade partners and the design team so we didn’t take out too much of the structure,” Fore said. “We shored up the building and divided it into quads for the work.”
Whenever possible, the team used original chases, including fireplace chimneys. For the rest, “Being that the building is wood masonry and brick, we had to channel to install most of the utilities,” Fore said. “To get our electrical in, we did very precision channeling. We only put them a couple inches deep into the wall to keep the integrity of the building.”
Coordination again proved key. “Because every piece of pipe, every conduit for wiring, and every piece of duct had to be individually channeled, we coordinated through 3-D BIM, then laid out in the field before channeling a trench into the wall,” Betts said.
The historic nature of the Capitol building required many other unusual construction techniques. Because of the wood structure, “We minimized any hot work and used electric whenever possible to avoid the risk of fire or fumes being absorbed,” Betts said.
That included electric mini-excavators, electric wheelbarrows, and electric conveyors to move out large quantities of excavated dirt.
In many instances, hand work replaced equipment. “Most of the exterior stone that had to be replaced was hand-carved,” Betts said. “Millwork restoration required hand work. A significant amount of the excavation under the Capitol had to be hand-dug because they couldn’t get equipment into the small rooms. It was a lot of reverting back to the old ways of construction.”
Replacing failing sandstone on the Capitol’s exterior also required traveling back in time. “The building’s stone came from a quarry in Rawlins, Wyoming, that hadn’t been open for over 100 years,” Betts explained. “The state was granted access to the private land and we reopened the quarry to get material that matched the existing stone. Knowing they had this one opportunity, the state had the foresight to have us quarry enough stone for the next complete exterior renovation that could be 100 years down the road.”
Construction on the Herschler Building, built in 1983, posed different challenges, with 300 state employees continuing to work in the building. “We broke our work into two phases,” Betts said. “After we finished the first half, we moved them to the renovated space, then finished the other half.”
The project’s new central utility plant now feeds the Capitol and the Herschler Building, as well as the Supreme Court and two other buildings across the street. Landscape and pedestrian improvements tie the grounds together in a park-like setting.