Where does ctl engineering perform services? Today, CTL Engineering regularly performs services not only throughout Ohio, but also in all of the Mid-Atlantic and Midwestern states. In addition to our corporate headquarters in Columbus, Ohio, we have expanded our service centers to include 12 other regional offices.Who is ctctl engineering? CTL Engineering is a full service consulting engineering, testing, inspection, and analytical services company. Formerly known as Columbus Testing Laboratory, the company was established in 1927 as a privately held independent engineering and testing laboratory serving the local community.Who is ctl group? We are an internationally recognized engineering, architecture, and materials science consulting and testing firm. Throughout the life-cycle of structures and infrastructure, CTLGroup experts evaluate the cause of problems, implement strategies to manage performance, and develop integrated solutions to resolve technical challenges.