CHICAGO, IL — 60 stories above the convergence of the Chicago River stands Salesforce Tower. At 835 feet in height, the newest addition to the Downtown Chicago skyline brings 1.2 million square feet of Class A office space to the River North district. The latest addition to Alvine Engineering’s impressive downtown Chicago portfolio comes off the heels of infrastructure work at the River North Tower, Wolf Point West, and Wolf Point North. Salesforce Tower Chicago is the finishing touch to the Wolf Point mixed-use-development, a joint venture envisioned by real estate developer Hines and Pelli Clark & Partners. A precise design drives the cutting-edge allure of the office space. The building features column-free corners, floor-to-ceiling windows with innovative glass technology, active outdoor spaces, and robust mechanical and electrical components that support Hines’ ambitious indoor environment objectives.

Amidst the rousing success of the tower’s construction were a myriad of obstacles. The project, originally envisioned and proposed in 2012, was impacted drastically by the COVID-19 pandemic. Along with an unprecedented supply chain slowdown, overall economic confusion, and a radical restructuring of collaboration strategy, Alvine Engineering and its partners were forced to quickly adapt to the uncharted terrain of construction amidst a full-scale pandemic. In-person meetings with suppliers and collaborators turned virtual. Interior layouts, construction coordination, and other future considerations now had to accommodate a post-COVID world of social distancing and hybrid work compliance.

As one of the few projects continuing construction throughout the pandemic, Salesforce Tower Chicago would become a trailblazing example of post-COVID office space. Additionally, the project would become a model for office-tenant talent attraction in light of the nationwide surge in remote work accommodations.

Unique Building…Unique Solutions

The Newcomer

HKS Architects (HKS) was new to Hines’ projects and was broaching new territory with partners they had never worked with before. Sean May, a Senior Project Architect at HKS, spoke on how their architectural team leaned heavily on the processes and relationships forged by Alvine Engineering along with other project team members.

“There were a lot of challenges trying to build a skyscraper during the pandemic,” Sean explained, “There have been questions about the feasibility of skyscrapers in today’s day and age. So, on top of adding more incentivized values for tenants to transition back to the office from remote work, the design team had to stay on top of deadlines and tasks despite product shortages and limitations on component testing.”

Sean noted the added challenge of collaboration with project leaders being scattered across the country during a time when COVID-19 severely limited travel. Shifting the collaboration strategy to a virtual arena and adding more meetings where the design team constantly refined and reiterated the developer’s vision was a critical factor in the project’s success.

“Chicago has a rich history of building tall buildings that make a lasting architectural impact,” Sean concluded, “There’s world-class design across the skyline, and now HKS Architects is a part of that. I’m very humbled and proud that I could contribute to the project.”

Opportunities of Scale

The mechanical system is comprised of a chiller plant on the bottom floor which pushes cold water to ‘nests of infrastructure’ on different levels of the building. A space of this size and scale required more infrastructure than would fit in a mechanical room. “Outrigger floors” that were originally designed by the structural engineer to hold cross-bracing and beams were not ideal for tenant use. So, they large air handling units and other vital infrastructure components were custom fit around the structural components.

“There are some air handling units that are the same size as a house,” Dan Karnes stated. “They were as tall as we could ship into the city and set to a size that ensured they could fit underneath the bridges of Chicago as they were transported to the construction site.”

Dan Karnes is an Alvine Engineering mechanical engineer who led the mechanical design team, with oversight from Principle-in-Charge Steph Guy, on the Salesforce Tower Chicago project. He continued to state that some of the mechanical components and ducting were so large it had to incorporate portions of the structural beams inside of the ductwork as a solution for space constraints.

A vital piece necessary for meeting energy code requirements was thanks, in large part, to the centralized mechanical infrastructure which allowed for exhaust heat recovery from the restrooms on every level to be circumvented back to the central cooling plant. According to Dan, this strategy was advantageous in earning seven LEED energy credits and Gold Certification.

Another interesting design portion, prompted by the sheer scale of the plumbing system, was an intuitive reclaimed condensate mechanism. The design collects condensation, normally wasted, from the building’s hydronic piping and redistributes the water to a tank that cleans and feeds the plaza irrigation systems. It is projected that the system will reclaim tens of millions of gallons of water throughout the building’s lifetime.

Utility Stacking

In addition to changes, addendums, and other design decisions being made in light of COVID-19, some of the most stringent design standards in the country were implemented within the Salesforce Tower Chicago project. Hines’ energy model and carbon emission requirements went well above and beyond the Chicago standard for efficiency and power consumption. Salesforce, the San Francisco-based anchor tenant for the project, brought ambitious energy goals to the table that were at the forefront of California’s innovative approach to energy conservation. Thanks to Alvine Engineering’s extensive relationship with Hines and a well-experienced portfolio in energy-efficient construction, the baseline electrical design met the demanding energy requirements of both entities with relative ease.

“We have a team that’s very comfortable pursuing those goals,” Kyle Weber, P.E., stated concerning the project’s energy code requirements. “We’re so entrenched in meeting those energy objectives that it wasn’t difficult for our team to provide a highly efficient design that met those standards.”

Kyle Weber is an Alvine Engineering project manager who was a lead electrical engineer on Salesforce Tower Chicago. While the tower is only the 17^th tallest building in Chicago, it cracks the list of top 100 tallest buildings in the United States by a wide margin (71^st). A building of this stature can offer unique design challenges for electrical engineers as pathways and services become more convoluted to coordinate in correlation to the height of the building. The design team devised a unique and innovative solution, coined “utility stacking,” to avoid complicated service routing for the electrical team.

“We dedicated a portion of each level as space for the electrical utilities, and that stacks throughout the building,” Kyle explained. “Designing the electrical service this way allows the structure to transform the incoming domestic power to the required voltage level on a floor-by-floor basis and simplifies electrical conduit routing, driving cost-effectiveness and simple constructability.”

The project was also built for WELL accreditation and set to achieve Hines’ market-leading quality standards with cutting-edge features: UV lights in air handling units that mitigate microbial growth, dual-level air filtration with perimeter foam gaskets to prevent filter bypass, and IoT-Driven C02 monitoring that adjusts outside air filtration based on occupancy.

The Spring of Things

The amount of care and consideration put forth by the teams involved to create an unparalleled aesthetic in office space is evident in noise-reduction infrastructure decisions and cleverly-integrated interior design choices that make this building an architectural marvel.

Every single hydronic pipe in the building is suspended by a spring, limiting the amount of noise generated by the HVAC system to ensure a noise-free working environment. Dan Karnes goes on to state that, while this added an extra layer of complexity to an already intricate project, this design choice speaks to the joint efforts of the architect and engineers ability to meet challenging project demands.

“Every pipe that would normally be sitting on the ground or a hanger is suspended by some sort of spring,” Dan explained, “Just the intellectual prowess needed to make all of those calculations and make that possible really speaks to the efforts of not only our engineering team but the collaborative mindset of the project as a whole.”

What’s Louver Got to Do With It?

There are instances in projects where the necessity for mechanical infrastructure overrides the architect’s vision of the building’s visual aesthetics. Louvers are a prime example of an idiosyncrasy that can stand at odds with a building’s façade. Louvers are exterior vents that are designed to reject sunlight and water penetration into a structure but allow outdoor airflow into a building.

The architectural team worked in conjunction with Alvine Engineering’s mechanical engineers and the structural engineer to create a one-of-a-kind offset curtain wall that effectively hides the louvers while also providing a breathtakingly seamless exterior glass wall.

“On other projects, most architects would just accept the louver as a necessary mechanical function that breaks the architectural aesthetic.It can be cost prohibitive to attempt reworking intakes and protection against the elements,” Dan Karnes reiterates, “On this project, however, the louvers completely disappear.”

A Cascading Effect

An additional tenant joined late in the design stages and requested to add multiple kitchens along with other amenities to the design. What may seem like a minor change to the building’s master plan would have a cascade of effects on the building’s overall calculations and design. In response, Alvine Engineering’s team went back to the drawing board to assess every electrical and mechanical decision to better understand managing a change this late in the design phase. In the end, our firm’s engineers were able to effectively accommodate the request.

“As engineers, when we receive a unique and challenging request like that comes in, we go back and assess everything from the basics,” Kyle explained, “So, we dig into every decision we’ve made to see how we can accommodate and what we can make work.”

Despite the obstacles presented by the new design challenge, Dan Karnes highlights the client’s trust in Alvine Engineering’s ability to effectively administer the changes to the design. Where other developers may refuse the request, Hines chose partners with proven track records in innovative solutions and a mindset that drives trailblazing solutions to fruition.

Questioning What’s Possible

Despite economic slowdowns, limitations in travel, product shortages, and challenging design obstacles, the Chicago Salesforce Tower stands tall along the Chicago River. A testament to a design team that explored innovative options with open minds, trailblazed genuinely unique designs and executed despite limitations that slowed construction to a nationwide standstill.

“This is an iconic piece of Chicago,” Kyle concludes. “There are a lot of projects that have their challenges and complexities, and this project was no different, but what made this a truly stand-out development was how the team came together to bring this iconic piece of architecture to the city during an unprecedented time in the industry.”

Behind every unique building integration and architectural marvel, there was a group of people that drove every decision, calculation, model, and design and worked fervently to bring it to life.

Learn more about Alvine Engineering’s Chicago project portfolio here.

Kyle Weber

Kyle is a Project Manager and an electrical engineer with 10 years of experience.  Kyle earned a Master’s degree in Architectural Engineering from the University of Nebraska—Lincoln in 2014 and has been involved in the firm’s most technically sophisticated and high-profile electrical design projects.

Dan Karnes

Dan is a LEED-accredited mechanical engineer who has been designing some of the firm’s most complex mechanical systems since 2019. Dan earned a Master’s in Architectural Engineering from the University of Nebraska at Omaha in 2015 and specializes in systems layout, energy studies, HVAC system design and life cycle analysis.