Grange Insurance Headquarters Expansion - Office Tower and Parking Garage

Grange Insurance Headquarters Expansion - Office Tower and Parking Garage

Columbus, OH

Owner
Grange Insurance
Construction Manager
Gilbane, Inc.
Architect
NBBJ
Completion Date
2009
Construction Cost
$90 million
LEED Certification
LEED/Sustainable Design Integration
Awards
2009 - Merit Award-AIA

Located in the historic Brewery District in Columbus, Ohio, the project consists of a 10-story addition to the existing 12-story office building, a two-story data center and a new 1,000-space parking garage. The new office building and data center are steel-framed structures, and the parking garage is post-tensioned cast-inplace concrete. There were several design challenges on this complex project. The new office tower and data center needed to blend in with and enhance the appearance of the existing tower as well as address the urban aesthetic of the Brewery District. The office layouts of the new tower needed to merge seamlessly with the existing office floors. This dictated a 35-foot by 35-foot bay size – a large bay size for an office building. In addition, it was determined to use an under-floor air distribution system. This required a 1-foot deep raised floor system and the new floors had to align with the floors of the existing office building. These factors resulted in a less than optimum depth for the floor framing system, which consists of a lightweight concrete slab on composite metal deck on high strength structural steel framing. The girders were fabricated with large web openings between the infill beams to facilitate air distribution.