The 300 N. LaSalle project is expected to bring new attention to the Chicago riverfront, with office, retail and restaurant space.

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The Chicago River plays an important part in the city’s history, its banks having served as the site of the area’s first settlement, as well as its role in helping the city become a transportation hub. Today, Clark Construction is working to give the Chicago River a new role in urban development, one that will make the new 300 N. LaSalle office building one of the greenest in the city.

A cooling system that uses water drawn from the river is just one of the sustainable features included in the 60-story office building, according to Project Manager Stephanie Calhoun. She says the project is aiming for a LEED Gold certification when the building is completed in December.

Located on the north bank of the Chicago River in the city’s downtown, 300 N. LaSalle is a 1.5 million-square-foot commercial project that will include 52 levels of office space, seven levels of mixed-use and three floors of underground parking. This is the latest in a portfolio of projects Clark has undertaken for the Hines, the building owner. Calhoun says the company’s last project for the owner was the Takeda Pharmaceuticals North America Headquarters in Deerfield, Ill., and prior to that the 191 N. Wacker office building, also in Chicago.

Calhoun says the company’s previous experience with the owner and high-rise projects in the city, along with its more than 100 years of total experience in the construction industry, are what made Clark the preferred contractor. “Our reputation preceded us,” she says.

Building Green
Some of the most compelling features of 300 N. LaSalle are the sustainable and green elements. “One of the unique features that’s in-line with the U.S. Green Building standards is we’re actually using river water for our cooling system,” Calhoun says.

The intake for the cooling system is located on the east side of the project, and the outtake on the west side. The system will reduce the building’s energy consumption by circulating river water to cool the air in the HVAC system.
Calhoun says other green features include a green roof to reflect sunlight and keep the building cool, as well as using recycled and local materials. The construction process so far has also been very green, she adds.

“As far as the construction side of things go, we are on track to achieve both of the [LEED] credits for construction waste,” she says. Clark has been able to keep up to 90 percent of the waste generated on site diverted from a landfill. The parking garage that once sat on the property was demolished and nearly all of the materials were also recycled, Calhoun says. Many of the materials being used in construction have low VOC content, which is meant to improve the air quality of the building’s interior for its visitors and inhabitants.

A Young Giant
The 300 N. LaSalle project is expected to be one of Chicago’s tallest buildings once completed, at more than 800 feet in height. Designed by Connecticut-based architectural firm Pickard Chilton with Houston’s Kendall/Heaton Associates Inc. as the architect of record, 300 N. LaSalle features a facade made of a unitized curtainwall system with stainless steel accent covers. Metal panel buttresses top off the building.

The core of the building is constructed of concrete caissons, grade beams and foundation walls, and concrete core and shear walls. The 59 upper floors of the building feature structural steel framing and concrete slabs on metal decks.

Shaky Ground
Building on the river has been an interesting challenge for Clark, Calhoun says. For instance, before installing the building caissons, the company had to deal with an existing freight tunnel that ran under the site. This has made excavating and retaining earth on the site “a good challenge,” Calhoun says.

The tunnel at one time was used to bring coal to buildings along the river, but had fallen into disuse. It was U-shaped and had another, smaller tunnel running out of it. In 1992, work being done to a nearby bridge accidentally breached the tunnel walls and caused the Chicago River to leak into it, causing a flood that crippled the downtown Loop area and resulted in nearly $2 billion in clean-up costs.

To prevent a similar disaster from occurring during the construction of 300 N. LaSalle, Calhoun says Clark had to think ahead and plan accordingly.

“We had to bulkhead off the tunnel at the property line and grout it solid,” she says. “To achieve this we had to drill access tunnels to physically get workers and eventually grout into these tunnels,” she says.

Boxed In
Aside from the tunnel on the site creating a challenge, building along the Chicago River also provided a series of logistical challenges that Calhoun says threatened to slow down construction. “We have the river to our south, we have a building on our west and on our east is LaSalle Street, which is a heavily traveled street leading across the river and into the Loop,” she says.

Additionally, the site is bordered on the north by private property. All of this adds up to extremely limited access points to the construction site. Over 50,000 cubic yards of soil had to be excavated from the site, as well, so Clark turned to barges to move material and equipment to and from the site on the river. “We’ve used it to bring in equipment, remove equipment,” Calhoun says.

“The proximity of the river has been very challenging, in that is was one less place we could get trucks.”

Even though building along the Chicago River has been a challenge logistically, Calhoun says it has not been any more dangerous to work on than any other site in the city.

“I would say it’s about the same as any urban situation,” she says.

In general, Clark’s work force is well-prepared for working safely, Calhoun adds. She says all employees receive 10-hour OSHA training, and weekly orientation meetings are held on the job site to bring new employees up to speed on the company’s procedures. Successful completion of the company’s training is documented with stickers for employees’ hardhats as a visual reminder.

Being Prepared
Another challenge for Clark involved the building’s 41st and 42nd floors. Calhoun says those two were designed to be transfer floors, for structural outriggers with large steel plates embedded in the concrete core walls for stability. She says the team planned the installation out over six months to ensure safety and efficiency for that phase of the project.

On this phase and the other logistical challenges posed by the project, Calhoun says there is no better solution than thinking ahead.

“I would say planning prior to the execution of the difficult sequences of this project and looking ahead to logistical challenges [are essential],” she says.

“If we hadn’t thought and planned ahead, we would not have been able to successfully execute many portions of this project.”

Calhoun also credits the numerous subcontractors working with Clark for the project’s success so far. Many of the subcontractors working with Clark on 300 N. LaSalle also worked with the company on the expansion of McCormick Place in 2007. “So, we could understand their capabilities,” Calhoun says.

“Having the right subcontractors can make all the difference.”

‘Wonderful Addition’
Working with the city has been a learning process for Clark, Calhoun says, and she sees the 300 N. LaSalle project as an improvement for the city’s riverfront. “It’s been enlightening and challenging at the same time,” she says of Clark’s relationship with the city of Chicago. “Most of the people we’ve met with have the same goal, which is to build [this project].”

A waterfront café and half-acre public plaza will be part of the property once completed, along with retail space. The building’s anchor tenant will be law firm Kirkland & Ellis LLP, which was founded in Chicago. Calhoun says she believes the building will attract new business and attention to the area and stimulate the Chicago riverfront.

“I think it’s a wonderful addition, it’s exciting to be part of building this project,” she says.