Lorenz Lechler was a late 15th-century German master mason who composed Instructions, a booklet on gothic design, and who contributed to the Heidelberg Church.
[4] He writes that "[a]n honourable work glorifies its master, if it stands up," and goes on to show how elevation measurements are taken from a ground plan specifically in the construction of a late medieval German hall church.
[6] The treatise is described as "unsystematic" in its treatment of the different structural components, including "canopies, [the] orientation of the choir by means of a compass, tower (strength of the wall and of the foundation), pile-work, tracery, ... pinnacles of various heights, and gables.
"[7] In addition, because it describes a simple church hall rather than an elaborate 13th-century Rayonnant-style French cathedral, its content should not be generalized to all period masons or construction methodologies.
[7] Known as the Unterweisung in German, Lechler's Instructions comes to us via a 16th-century notebook belonging to Jacob Feucht von Andernach, which also included a copy of Matthäus Roritzer's Booklet Concerning Pinnacle Correctitude.