The number of visitors to the garden has grown from 250,000 in 1982 to more than 1 million in 2018. The new center enables the garden to handle the higher visitor flow and to host community events, indoor weddings and seminars on botany.

One of the first challenges for the construction and design team was how to keep the flow of visitors into the garden during construction.

“The phasing was, I think, one of the better ideas we had on the project,” says Austin Davis, senior project manager. “Our idea was, why don’t we build a portion of the structure, which is the events center, put a roof on it, put the skin on it, but we won’t fit it out to its final condition until a later phase of the project.

“Meanwhile, 30 feet away, we were building the remaining 80% of the project in the existing footprint,” he adds.

Instead of a tent or other makeshift structure, the events center was constructed as a temporary visitors entrance with scaled down amenities including bathrooms, a gift shop and a grab-and-go café.

LED lighting in the event center can change color based on user preference.
Photo by Casey Dunn

Historic Building Updated

The project included the renovation of the 2,100-sq-ft historic Linnean House, which was built in 1882 and is the oldest continuously operating public greenhouse west of the Mississippi River.

The design team was tasked with renovating the facility while maintaining the historic structure and aesthetic to ensure the renovated structure complemented the historic architecture.

The team replaced wood windows with fiberglass ones and created a new vista for visitors to enjoy.

“There used to be a brick wall at the back of the structure,” Davis says. “We cut a hole in it so when you come out of the events center, you go straight to the Linnean House and you can see all the way through [the hole] to a garden beyond.”

 

Preserving Plant Life

Preserving unique plants and trees was one of the project’s greatest challenges and required close coordination with the owner.

“It was more difficult to work around the plants and trees than it was the historic buildings,” says Phillip Lee, vice president of operations at Alberici.

To protect two treasured ginkgo trees, the team created circular root protection zones that extended to the farthest leaves—the driplines—of the trees. The zones were marked with signs noting that if any work was to be done near the trees, the garden’s horticulturist needed to be contacted.

“We’d say, ‘Hey, we’ve got this 1-inch PVC pipe that needs to come through here for irrigation,’” Davis says. “‘How do we approach this? Can we dig in this area? How deep can we go?’ So it was constant conversation with horticulturists to be sure we weren’t doing anything affecting the long-term sustainability of these plants and trees.”

Smaller equipment was used and it needed to be cleaned often so it wouldn’t drip any harmful substances, such as oil, on to the trees and plants.

“It was also important not to over compact the soil to the point where roots wouldn’t grow,” Davis says. “So the garden was very adamant about the size of the equipment we used.”

Working with a landscaper, the team refreshed soil in plant beds.

“There were a least a half dozen different soils that would go in any certain planter bed,” Davis says. “They had to be 18 in. to 36 in. deep depending on the size and type of the plants.”

At the same time, numerous concrete sidewalks were laid to allow visitors to get close to see the plants.

“There was a lot of concrete work done around very delicate and unique plants,” Lee says. “Typically, under a sidewalk you are filling in as much rock as possible because you know that rock is not going anywhere. But we had to do the right soil mix to allow the plants’ roots a place to grow underneath the sidewalk.”

In another case of working with plants, they reused an existing tree that had come to the end of its life.

“They utilized the wood from the tree to create a really cool bench in the main entrance of the lobby,” says Jim Kappeler, senior project principal for IMEG, which handled mechanical, electrical, plumbing, fire protection and technology design.

The visitor center is a gateway to the garden.
Photo by Casey Dunn

Reusing Rainwater

One of the focuses of the botanical garden is on sustainability. IMEG helped them reuse rainwater for watering plants “because, in their words, rainwater is liquid gold,” Kappeler notes.

The project required two 25,000 gallon rainwater tanks, which help the garden save on operating costs.

“We were able to integrate them into the design of the facility,” Kappeler says. “Once the water is collected, it goes through a treatment process before it goes to the plants. And it saves them from buying city water.”

The tanks were buried underground, but “it’s a pretty compact site so finding a footprint to bury those tanks was a bit of a challenge,” Kappeler says.

A conservatory with glass walls and roofs to create a temperate environment for growing plants native to the Mediterranean was another part of the project.

“It needs to stay between 75 and 85 degrees year-round so we air-conditioned the conservatory to maintain those conditions,” Kappeler says. “That actually required a lot of detailed coordination and design to make happen.”

The conservatory is served by a couple of air handling units connected to underground ductwork to condition that space, and all of the systems are on backup power because if they lose power all of those plants would die, he says.

The center’s entryway was refashioned to surround visitors with the garden’s plants and trees as soon as they step foot into the garden site. The project also greatly increased accessibility to the garden, with additional accessible parking, restrooms, family restrooms, a Calming Corner room as well as hearing devices and technology for those with hearing impairments.

Walking through the center on a cold, windy winter day, Kappeler was thrilled to see how well the HVAC systems were working, particularly in the conservatory.

“When I was there, I couldn’t have been more comfortable,” he says. “The HVAC system was working very well. It’s a very complex building that required a lot of detailed coordination with the entire design and construction team to make work.”

Lee credits the garden ownership with playing a huge role in the success of the project.

“It’s not every day that you get great clients that really put their shoulder to the wheel with you to work out issues,” he says. “They wanted to learn. They wanted to help us. We knew we were working with someone we could trust, and we were all working in the same direction.”

“People are what make a project go smoothly,” says Deniz Piskin, vice president of facilities and construction for the garden. “The partnership between IMEG, Alberici and the garden construction team was focused and determined. Communication was key, and it occurred very often.”

Davis looks forward to showing his children the garden.

“I think it’s very rewarding to know that the garden is something that thousands of people will visit every day,” he says. “That I had a small part in it is really kind of neat. I’m going to walk up those steps one day and tell by children, ‘Hey, Daddy helped build this.’ Hopefully they will be excited by that.”