During the SIXXI research (“XX Century Structural Engineering: the Italian Contribution”, ERC Adv Grant, PI: Sergio Poretti, Tullia Iori) special study tools supported historical surveys on works. The experimentation on tools became an autonomous research topic, developing itself from the “reconstructive re-drawing”, pioneered by Poretti in the mid 1980s, up to 3D modelling and 3D printing. This paper resumes briefly its starting and illustrates most recent outcomes, as a board field of research in Construction and Structural engineering History.