The Consulting Engineering firm KALLIERGOS O.T.M. S.A. has a lead role and participation in all major infrastructure projects in Greece and a strong presence in similar projects abroad. Founded in 2004 via an internal restructuring of the operating since 1965 mother Company O.T.M. Ltd, it continues the tradition of offering high quality services to State Authorities, General Contractors and Private Equity Organizations. The firm is based in Athens, Greece, housed in private premises. Combining the vast record of experience and the highly qualified Engineering Staff, the company has the capacity and resources to apply state-of-the-art methods of Structural and Earthquake Engineering for both new and existing infrastructure, industrial and residential facilities, to projects of any size and level of complexity. In parallel to its renowned design potential, the company has extended the range of professional services by implementing state-of-the-art BIM methods in multiple software platforms (TEKLA, Revit, Civil 3D). KALLIERGOS O.T.M. currently employs 17 engineers, 5 CAD-BIM technicians and 4 administrative employees. Across all operations, the firm applies a Quality Management System conforming to EN ISO 9001:2015, certified by TÜV HELLAS (TÜV NORD) S.A., while its additional certifications — ISO 14001, ISO 37001 and ISO 45001 — underscore its unwavering commitment to responsible, transparent and high-standard business practices.