Encompassing an entire block in downtown Aurora, Cordogan Clark & Associates' projects for Old Second National Bank have included more than 100,000 sq ft of additions and remodeling to their original 1924 George Elmslie building, which is listed on the National Register of Historic Places. A 30,000 sq ft addition and a new 10-lane drive-through/office facility are all detailed with materials contextual with the original structure.

When the Old Second National Bank in Aurora, Illinois planned a major addition to its historic main facility, there were a number of avenues the design could take. The original building's striking design made it easily identifiable and one of the most memorable buildings in downtown Aurora. After reviewing alternate courses, it was determined that a more literal reinterpretation of the original architecture and detailing would best reinforce the original building's image, and therefore the bank's image within the community.

Many of the original building elements were of unique origin: the roman brick from Ohio; terra cotta from San Francisco; and granite from Massachusetts. Fortunately, after researching the original construction, it was found that many of these elements were still available, and many were obtained from the original manufacturers. Old Second's investment in design authenticity and construction integrity is a strong and well-recognized civic commitment. This helps enhance the Old Second's status as a pre-eminent financial institution.