Project Highlights

• Retrofit of warehouse into lab space
• Major reinforcing of structure to meet vibration criteria
• Chiller support platform

Overview

With lab facilities scattered across the metro area and a growing need for additional space, Allina Health System chose to centralize its laboratory services into a state of the art central lab by retrofitting its existing warehouse adjacent to Abbott Northwestern Hospital. The $29 million project comprises 76,000 square feet of lab space and 3,000 square feet of office space to accommodate 400 employees. Structural changes to the existing building included creating several mezzanine spaces, a platform at the roof to support a new chiller, and an extensive Unistrut system above the lab that not only lowered the original 28-foot ceiling to 9 feet, but also houses and supports ceiling grids, diffusers, electrical fixtures, and mechanical systems for more efficient use of space. The most significant challenge, however, was vibration mitigation for highly sensitive microscope equipment within the lab. The original 4-story building has typical gravity systems consisting of composite steel beams and composite steel deck and lateral systems consisting of braced frames. The existing steel girders typically span 36 feet and purlins are spaced approximately 9 feet on center spanning 36 feet. While the existing building structure was adequate for strength, it needed major reinforcing to meet the challenging vibration criteria. Several options were studied, resulting in the stiffening of the existing structure from underneath with new beams and girders and by cutting down the spans of existing beams. The specialized mitigation plan required 500 tons of steel. Despite a tight schedule and a complex process, the team concluded the project on time, helping make the lab centralization a smooth process.