Workers install a floor light fixture in the museum that will stand five stories.
Photo courtesy of the Nature & Culture Museum of Wisconsin

Bringing the architects, construction management team and exhibit designers together for a road trip at the height of the COVID-19 pandemic created a strong foundation for team building and a level of planning necessary for a highly complex project.

“It was a good way to bond,” says Dr. Ellen Censky, president and CEO of the museum. “We had a lot of hard conversations and we worked our way through it because we all have trust in each other.”

The trip also introduced the team “to the amazing landscape and people of Wisconsin. It inspired the team,” she says.

Construction of the new Milwaukee museum began in the summer of 2024, with completion anticipated for 2027.
Photo courtesy of the Nature & Culture Museum of Wisconsin

“From a construction management perspective, the road trip really helped us establish a solid understanding of the vision for the project,” says Kurt Theune, Mortenson vice president and general manager. “For any construction project, we’re natural problem-solvers. But it really helped us frame the bounds for which we needed to solve problems and to work through issues or propose alternatives, knowing that there were some things that were absolutely uncompromisable.”

Bringing together the architect, construction manager and exhibit designer early on and at the same time was “the right thing to do. We all grew in our understanding together, and that’s super critical for building a cultural landmark for the city,” he adds.

One place where the team stopped was Mill Bluff State Park in central Wisconsin, known for its dramatic, steep-sided sandstone bluffs and unique geological history.

Those rock formations inspired the museum’s exterior design, which is comprised of large, sculptural precast concrete panels mimicking the bluffs. Plans also call for three entrances to the building symbolizing the three rivers that come together in Milwaukee. They each will terminate in a central area planned as a gathering space in the structure being built at North 6th Street and West McKinley Avenue in the Haymarket neighborhood in the city's downtown.

“The word Milwaukee in Potawatomi means gathering place by the water, and this is a gathering place," Censky says. "So everything about this is symbolic, and the site we chose was very specific. We wanted to be close to the neighborhoods that we serve and not be sitting on the lakefront.”

The museum’s interior will have five permanent galleries titled: Time Travel, Wisconsin Journey, Milwaukee Revealed, Living in a Dynamic World and Rainforest. There also will be a planetarium, butterfly vivarium, a rooftop garden, a café and an outdoor plaza.

Workers install 70,000 plastic voids to reduce the weight of the building.
Photo courtesy of the Nature & Culture Museum of Wisconsin

“Ellen [Censky] gave us this amazing challenge when we started the project, which was to tell the story of nature and culture and how they intersect in not only Wisconsin, but also in Milwaukee,” says Jarrett Pelletier, principal at New York City-based Ennead Architects. “So we’re trying to tell a story that connects all these threads ... We took a lot of cues from what we learned [on the road trip], and that really generated shapes and materials and how we tell stories through architecture.”

The exterior features 670 precast concrete panels fabricated by Stonecast Products in Germantown, Wis. They vary in size, with some up to 35 to 40 ft long. The heaviest ones weigh up to 56,000 lb, or 28 tons.

“There were a whole lot more panels in the beginning, and it was much more expensive than we could afford,” Censky says. “The team came together and figured out how they could reduce the panels without reducing the way the building looked.”

To maintain the structure’s appearance while keeping costs in check, Theune says the team focused on the building’s corners—curved panels—which were shaped like upside-down cones in sections.

The construction and design team envisioned the building as a tilted cylinder form, which reduced cost and increased efficiency.
Photo courtesy of the Nature & Culture Museum of Wisconsin

“Initially, the bottom radius was larger and the top radius smaller, creating unique formwork for each segment,” Theune says. “Each level required a different form, which complicated construction. Working with local contractors, we reimagined the geometry into what we called a tilted cylinder—essentially an extruded cylinder—a cylinder that has been stretched along its axis. This change meant the same form could be used all the way up each corner, making all 12 corners of the building identical.”

Mortenson was "really good about bringing in [Stonecast Products] to talk to us about our design at a point when we could still make changes,” Pelletier says. “Through that, it helped us make sure these forms are repeatable even though the building has a very organic shape.”

The team also optimized other aspects of the precast process, including the pattern and texture on the forms, allowing for repetitive, reusable forms.

“We were able to cut hours and weeks and multiple people and steps out of the process to create those forms,” Theune says. “That’s where the expense dropped. It’s a really big deal when you talk about more than 600 panels. Getting it down to 20 forms that we can rinse, repeat and use again was crucial.”

Theune says that from a construction innovation standpoint, some of the building’s most interesting work is not what is seen on display—it’s in the means and methods used to create the building’s unique geometry.

No two floor plates are the same. There’s a curved light well in the center that changes as it rises and radiused walls throughout the planetarium spaces.

An 82-ft-high skylight and an organic, sculptural design are some of the museum’s compelling architectural features.
Photo courtesy of the Nature & Culture Museum of Wisconsin

“Concrete can be finicky, so our craftworkers had to innovate with their formwork and materials,” he says.

Crews used computer numerical control machines—essentially automated tools that are guided by computer programs—to cut, carve, drill or shape materials with extreme precision instead of using rough plywood cut in the field to ensure everything aligned perfectly and looked as intended.

“Those temporary forms disappear once the concrete cures, but the process was a game-changer,” Theune says.

With panels weighing as much as 28 tons, the team needed to reduce the load on columns, beams and foundations. They built the structure using 70,000 plastic void forms—called BubbleDeck—which reduced the weight of each floor and allowed for less steel in the building.

Theune says the BubbleDeck eliminated roughly 1,440 cu yd of concrete from the concrete decks. A cubic yard of concrete weighs, on average, 4,000 lb, which equates to roughly 5,76 million lb of eliminated concrete weight. Some weight was added back in for the weight of the bubble cages and balls, but the system lightened the structure by about 5 million lb.

A tower crane was installed in October 2024 for the five-story building.
Photo courtesy of the Nature & Culture Museum of Wisconsin

“To reduce the weight and the carbon footprint of the project was a really big win and success,” Theune says. “It allowed us to shape the building’s individual and unique floors most efficiently and made the most sense for the exhibit spaces inside the museum.”

Just like the bluffs it mimics, the building does not rise in a straight, vertical line. It grows in footprint as it goes up and is curved and canted.

The 150 craftworkers currently on site represent just a portion of the 700 who will work on the project at peak.

“These are some of the city and state’s best, and they’re applying all their skill and intelligence—essentially creating a work of art,” Theune says. “It’s inspiring to see even new apprentices, many from Milwaukee County, explain the three river concept and the reasoning behind the building. That combination of innovation, [craft quality] and pride is what makes a project like this truly remarkable.”

Censky says the project’s unique design and construction methods are inspirational. “I’ve been taking donors through [on tours] and I had one donor say, ‘I didn’t realize how transformational this is going to be. I thought you were just picking up stuff and moving it. I think I need to get more involved.’ Once people get in and see it, they are just blown away.”