The current state of research on the design and construction of late Gothic vaults is principally based on the interpretation of sources, but rarely on surveys of existing vaults. In particular the idea for the criteria upon which the radii of the single ribs and arches were determined (so-called "principal arch"), is found to derive from sources dating from later periods when Gothic vaulting was no longer generally practised. In fact, this interpretation cannot be supported by geometric surveys on existing vaults: the plain contradiction to the actual geometric properties of some of the vaults studied so far have called for a critical revision of this interpretation. For investigating the design criteria and procedures starting from the built object, and also debating the methodological aspects of using the "building as source", a rewarding subject is the vault with curvilinear ribs in the "Hall of Arms" in the Albrechtsburg at Meissen (Germany), which was built by Jacob Heilmann in 1521. This is due to its ambitious design, high quality of execution and good state of preservation. A detailed survey of this structure is presented, discussing different aspects of the design, construction, and detailing, e.g.: Investigations on the geometrical concept of the vault by means of "reverse geometric engineering", on the background of the problem mentioned above. Further, the stone-cutting of the single members of the vault, which offers interesting aspects of standardization and its limits in nerves with double curvature: standardization in medieval constructions has been object of discussion, but not yet studied in the ambit of late Gothic vault construction. The question whether and how the vault surface was determined in the design, being the principle structural feature working as a shell structure; this is of particular interest as the relation between the rib system and the shell is complex and has consequences on the stone-cutting of the arches. The question how the design specifications for the single rib members could be derived from the general concept of the curves (clarified in the survey); the context to the graphic sources and technical prose related to late Gothic vault design and structural design. The aim is to understand the entire design process, the criteria of the decisions taken, their relation to the contemporary theory, and the communication process which took place for the creation of this extremely demanding structure.

The current state of research on the design and construction of late Gothic vaults is principally based on the interpretation of sources, but rarely on surveys of existing vaults. In particular the idea for the criteria upon which the radii of the single ribs and arches were determined (so-called "principal arch"), is found to derive from sources dating from later periods when Gothic vaulting was no longer generally practised. In fact, this interpretation cannot be supported by geometric surveys on existing vaults: the plain contradiction to the actual geometric properties of some of the vaults studied so far have called for a critical revision of this interpretation. For investigating the design criteria and procedures starting from the built object, and also debating the methodological aspects of using the "building as source", a rewarding subject is the vault with curvilinear ribs in the "Hall of Arms" in the Albrechtsburg at Meissen (Germany), which was built by Jacob Heilmann in 1521. This is due to its ambitious design, high quality of execution and good state of preservation. A detailed survey of this structure is presented, discussing different aspects of the design, construction, and detailing, e.g.: Investigations on the geometrical concept of the vault by means of "reverse geometric engineering", on the background of the problem mentioned above. Further, the stone-cutting of the single members of the vault, which offers interesting aspects of standardization and its limits in nerves with double curvature: standardization in medieval constructions has been object of discussion, but not yet studied in the ambit of late Gothic vault construction. The question whether and how the vault surface was determined in the design, being the principle structural feature working as a shell structure; this is of particular interest as the relation between the rib system and the shell is complex and has consequences on the stone-cutting of the arches. The question how the design specifications for the single rib members could be derived from the general concept of the curves (clarified in the survey); the context to the graphic sources and technical prose related to late Gothic vault design and structural design. The aim is to understand the entire design process, the criteria of the decisions taken, their relation to the contemporary theory, and the communication process which took place for the creation of this extremely demanding structure.

The ambitious late Gothic vaults created in the 15th and 16th centuries with their complex shape and complicated meshes of ribs soaring along spatial curves, were extremely demanding in their geometric design. This regards both the design of the whole structure, as also the design specifications for the single stone elements which were prefabricated and fit together on the building site with astonishing precision. In consequence, the particular character of these structures and their geometric features are intrinsically linked to the design routines and the geometric concepts used by the Master Builders. At present, these procedures and methods are not well understood, because they are not documented in original drawings, and because they differ in principle from the modern practice. In consequence, necessary works of repairing and restoring cannot recur to any information related to the original design. Moreover, understanding the characteristics of information transfer from the design to the execution, would cast a light on the information society in which these constructions were created. In several case studies, the geometric concepts of the intricate spatial curve systems of late Gothic vaults have been clarified on the basis of detailed surveys and geometrical analyses carried out on the built objects. On this background, also the existing sources such as historical design treatises could be re-interpreted. In a collaboration between the research group working on the design principles of late Gothic vaults at the Technische Universität Dresden, and expert stone masons specialized on historical working techniques and practical stereotomy at the Cathedral Workshop Œuvre Notre-Dame de Strasbourg, the phases of the design process, such as full-scale drawings on the tracing floor and the production of full-scale models and samples of ribs and keystones, are currently investigated in practical experiments. As result, we propose a complete picture of the design process from the general concept to the setting-out of the single stone elements. Further, we are able to drive general considerations on the Late Medieval and Early Modern design practice for stone structures and trace a new interpretation of the early treatises of stereotomy.

The ambitious late Gothic vaults created in the 15th and 16th centuries with their complex shape and complicated meshes of ribs soaring along spatial curves, were extremely demanding in their geometric design. This regards both the design of the whole structure, as also the design specifications for the single stone elements which were prefabricated and fit together on the building site with astonishing precision. In consequence, the particular character of these structures and their geometric features are intrinsically linked to the design routines and the geometric concepts used by the Master Builders. At present, these procedures and methods are not well understood, because they are not documented in original drawings, and because they differ in principle from the modern practice. In consequence, necessary works of repairing and restoring cannot recur to any information related to the original design. Moreover, understanding the characteristics of information transfer from the design to the execution, would cast a light on the information society in which these constructions were created. In several case studies, the geometric concepts of the intricate spatial curve systems of late Gothic vaults have been clarified on the basis of detailed surveys and geometrical analyses carried out on the built objects. On this background, also the existing sources such as historical design treatises could be re-interpreted. In a collaboration between the research group working on the design principles of late Gothic vaults at the Technische Universität Dresden, and expert stone masons specialized on historical working techniques and practical stereotomy at the Cathedral Workshop Œuvre Notre-Dame de Strasbourg, the phases of the design process, such as full-scale drawings on the tracing floor and the production of full-scale models and samples of ribs and keystones, are currently investigated in practical experiments. As result, we propose a complete picture of the design process from the general concept to the setting-out of the single stone elements. Further, we are able to drive general considerations on the Late Medieval and Early Modern design practice for stone structures and trace a new interpretation of the early treatises of stereotomy.