The new cancer institute in Chicago offers state-of the-art treatment.

Experience in building health care facilities in urban settings proved invaluable for Mortenson Construction, Minneapolis, when it recently constructed a state-of-the-art cancer treatment facility in downtown Chicago.

Mortenson solved some significant construction challenges presented by the 10,000-square-foot facility's special equipment requirements and its location on the first two floors of a 26-story condominium building. The new facility is home to the CyberKnife Cancer Institute of Chicago, a program of Swedish Covenant Hospital, and the Michigan Avenue Radiation Center.

The medical facility required a reinforced foundation to support installation of vaults that weigh 2.5 million pounds and contain radiation equipment. Typically, caissons would be built with a mat slab foundation installed on top, but that approach was rejected as too costly and time-consuming.

Instead, Mortenson inserted two foundations within the building's existing foundation. The construction team first cut a rectangle out of the current slab, then dug down 5 feet to the landfill upon which the building rests. The team then installed grade beams and laid a 12-inch mat slab on top, creating a foundation that "floats" on top of the first foundation.

Mortenson also broke new ground with the facility's mechanical system, which maximizes space while reducing long-term operating costs.

A typical ducted variable-frequency drive system with a dedicated mechanical room would have taken space needed for clinical and other uses, so Mortenson and its design partners developed a variable refrigerant flow system. The energy-efficient technology is smaller, has lower operating costs and provides better control for occupants as each room is equipped with climate-control units.

"Mortenson's experience in health care construction, especially in urban settings, made a huge difference," says Kerwin Brandt, chief executive of Accelitech LLC, a Chicago-based national developer of stereotactic radiosurgery and cancer treatment centers.