The Chicago Board of Trade Building™ consists of two buildings: the original 1930 Holabird & Root building (North Building) and the 1982 South Annex (South Building). Klein & Hoffman has been providing engineering services to the Chicago Board of Trade Building since the 1980s. The roof deck was added to the 23rd floor roof of the South Annex to enhance the buildings tenant amenities. A new hydraulic elevator was installed to provide access from the 22nd floor to the roof deck level.

Klein & Hoffman provided a full scope of structural engineering services related to feasibility studies to the development of construction documents and execution of construction services. The structural design included analysis of the existing capacity of the roof structure to support the required roof deck loading, design of two trellis structures, guardrail base connections, reinforcing the existing structure for the new elevator loading, and coordination with the architect to address uplift concerns on the pallet IPE deck system. Reinforcing of the existing structure was required to accommodate the new elevator loads; however, the existing concrete roof topping was able to be removed to reduce dead load and allow for the increase live load required for roof deck occupancy. We worked closely with the project team to evaluate cost effective solutions for the new elevator access to meet the project budget and the existing building constraints.