Most of the i’s are dotted, and many of the t’s are crossed, and by this time next year, we should see a shiny new skyscraper and lush new park rising along the banks of the Chicago River in the West Loop.
The building is 150 North Riverside, designed by friends of the blog, Goettsch Partners, and being developed by O’Donnell Investments. It will rise 53 stories on a chunk of land that has been mostly railroad tracks for at least a century. An 1898 map of Chicago shows one small six-story warehouse there, and the rest industrial wasteland used as space for for unloading ships.
The block’s industrial past will be concealed beneath a large public park, with the tower rising in the northeast corner of the property bounded by Lake Street, Randolph Street, Canal Street, and the Chicago River. North West Water Street goes bye-bye.
Steven Nilles is a partner at Goettsch Partners working on 150 North Riverside. He describes his role as, “I work with design director Jim Goettsch and senior designer, Joachim Schuessler from day one in developing our design concepts, collaborating with our engineering and specialty consultants, general contractor, subcontractors and material suppliers.”
He’s also agreed to answer your questions about the new building he’s working on. Below are questions submitted by Chicago Architecture Blog readers, and his e-mailed responses.
Q: Tell us about the shape of 150 North Riverside and how it came to be.
A: The shape of the tower evolved from the dual requirements of an efficient floor plate, as demanded by tenants in the marketplace, and the site constraints imposed by adjacency to the river and Amtrak rail yard. A structural core supported concept allows all members to be located within the boundaries of the site. A typical floor plate size of appox 29,000 gross square feet was developed around a concrete core element, which provided optimum lease spans, elevator performance, MEP [mechanical, engineering and plumbing] and egress, for current class A+ office occupancy of appox 1,200,000 square feet. The 245-foot by 125-foot floor plate is transitioned to a 150-foot by 40-foot core between the 4th and 8th levels. As in all core-supported buildings, loading symmetry is very important to allow equal and opposite reactions to efficiently transition the dead loads from the perimeter to the core with tension members at Level 8 and compression members at Level 4. Although the tower massing is articulated at the east side above level 48 providing occupied terrace areas, a balanced design is needed across the north-south axis to achieve an efficient core supported design.
Q: Between the river and the streets and the train tracks and an adjacent residential building, 150 North Riverside is located in a very complex site. Tell us about the challenges involved in finding the right place to site the building.
A: Our development is bounded and constrained by the river and river walk requirements to the east, Amtrak clearances and ventilation requirements to the west, and city bridge-supported public ways to the north and south. The Amtrak right of way determined the location of the west face of our core wall and the sloped property line determined the buildings floor plate size and locatioin at the southeast corner. These boundries essentially dictated the location of the tower.
Q: The building’s core is in a pretty tight space between the Amtrak tracks and the Chicago River. Did you have to do anything unusual with the foundation to put such a tall building on such a tight spot?
A: Based on the dimensional constraints of the site at grade and allowable floor plate geometry above grade, we developed a core plan which accomodated all our vertical services and structural parameters needed for an efficient structural design to resist the tower horizontal wind loads with a maximum width of only 40 feet. The core is supported on a 10-foot-deep mat structure with 16 10-foot-diameter rock socketed caissions below, designed for tension and gravity loads.
Q: The building’s facade features fins. These are features we normally see in warm climates like south Texas and the Middle East to cut down on heat. Do they serve that function in this building, too, or are they ornamental?
A: The fins do have a benifit on cooling loads and solar shading in the summer months. The magnitude of savings is being analysed for inclusion in the energy model.
Q: From the drawings, the building appears very blue and very vertical in an area of great horizontalness (trains, river, bridges, Randolph Place Lofts, etc…). How does 150 North Riverside relate to its surroundings?
A: Our facade design and articulation emphasizes the vertical nature of the 53-story office tower. The base of the tower is detailed solid to define the sturctural components with open areas maximizing transpearancy through the use of fin and cable glazing technology and non reflective-coated low-iron glass.
Q: 150 North Riverside incorporates a number of public spaces at the waterline and below the park. How are these insulated from the noise and vibration of passing trains?
A: The amenities platform below the tower including restaurant, fitness center and conference center is isolated from train noise and vibration by the massive four-foot-thick concrete core and crash walls at the west edge of our parcel. The public areas above the tracks are supported on roughly one-foot-thick concrete slabs and precast concrete, which in turn is supported on foundation elements which bear on bedrock. As such, we are fully isolated from noise and vibratory from Amtrak trains.
Q: 150 North Riverside appears to be a visual cousin to Goettsch’s 111 South Wacker. How are the two related?
A: Both 150 North Riverside and the original design for 111 South Wacker are core supported structures. Both towers had site constraints (for 111 South Wacker, the square site and immediate building adjacency to the east) for which core-supported design is an effective solution.
Q: 150 North Riverside appears to be a twin of some of the Sowwah Square buildings. How is it different?
A: The Sowwah Square office towers are also core supported structures. The Sowwah towers are constructed with post tension concrete core and frame and are roughly 250 feet shorter than the 150 North Riverside tower. The Sowwah towers also feature active solar shading and a thermal pillow double wall system for enhanced cooling. The taller 150 North Riverside tower features undulating glass fins on its east and west facades, offset core enclosure, occupied balconies to the east, steel floor and column framing to reduce dead loads, and a tuned mass damper atop to control drift accelleration.
Q: While the base of 150 North Riverside is very engaging, the top lacks the same drama. Is this an intentional effort to keep the focus on the park, or just a function of necessity?
A: The top of 150 North Riverside is stepped back at the northeast and the southeast corners and the core enclosure is offset to the east. These refinements may not be reflected in published renderings to date. Per requirements denoted for a core-supported structure, the dead load of the tower needs to be balanced about the central axis to effeciently transfer the [load to the] perimeter columns, so sigfigicant tower massing articulation opportunities were limited.
Q: New buildings always make the neighbors nervous about views and shadows. How did you address the concerns of the people at Randolph Place Lofts?
A: Our tower is located on our east property line, providing the maximum possible separation (122 feet) between our project and Randolph place to the west. For the sake of reference, Wacker Drive and Michigan Avenue at Oak Street are 125 feet from sidewalk to sidewalk— meaning that Randolph Place enjoys a setback equivalent to the widest streets in the central business district. Our project now provides the neighborhood with a landscaped park in lieu of the current open track condition below, a significant improvement relating to noise and air quality. As our tower is east of the adjacent residential building, and our short axis geometry is north-south, primary shadows from our tower footprint were minimized.
Q: Feel free to brag about anything about the building you think is cool that people haven’t noticed.
A: Despite the constraints of the site, we believe our project provides all of the atributes of a best-in-class Class A+ office development plus a significant inprovement to the riverwalk and an active park with an amenities platform for the public and tenants. We understand the responsibilities and demands for this most important site and believe our project will be appreciated by neighborhood residents and tenants alike.
Editor’s note: Thanks so much to Steve Nilles for taking the time to participate in this.