After his graduation from Technical College, direction civil engineering and 18 months of service, Taco Klevering started as a draftsman at Bartels Lochem. It soon appeared that he had the capacity and knowledge to perform calculations for standard timber frame homes. He became very experienced in calculating steel and concrete structures. In the early nineties Taco pioneered with Chiel Bartels (Bartels's founder) in establishing Mekap, a company that developed and sold fertilizer caps.
In 1999 Taco became responsible of Dunning BV in Apeldoorn as office director. Dunning was an engineering company, later acquired by Bartels. During that period he made the first steps to introduce fire safety engineering into the Bartels' organization.