Big-open-real-BIM Data Model - Proof of Concept

The goal of Building Information Modeling (BIM) is the continuous use of digital construction models from the planning stage onwards. The affected processes are iterative and involve multiple stakeholders who work at varying pace and in varying levels of detail. These stakeholders require highly specific tools based on diverging data models. To satisfy all those requirements one of the best known Open BIM implementations – IFC – offers a data model containing more than one thousand different types – from basic to highly specific. Due to its complexity, potential users must undergo prolonged training. The even bigger challenge for IFC, however, is keeping up with the updates of building regulations or with the ever expanding state of the art in simulation tools. Our approach, SIMULTAN, in contrast to IFC, consist of 26 different basic types. They can be combined to increasingly complex models, which can themselves be used as types for other models. This enables each domain expert to create a custom data structure for any specific task, which is automatically compatible with the data structure of any other domain expert using the same basic types. It shortens the training time and facilitates the loss-, corruption-, and conflict-free exchange of information between domain experts, which is a key aspect of BIM. As a use case, we present the calculation of the U-Value of a multi-layered wall. We compare number, complexity and adequacy of the necessary data modelling steps in IFC4 and in SIMULTAN. The result shows that the flexible data model of SIMULTAN can be better adapted to the task. Another significant advantage of SIMULTAN is its inbuilt separation of responsibilities at the level of the most basic types, which, when combined with secure transaction technologies, can enable safe, effective and easily traceable interaction among stakeholders

Shape Grammars for Architectural Heritage

Shape grammars have been introduced in architectural theory some decades ago. They have been applied to architectural construction methods (e.g. Chinese traditional wooden buildings) or for analyzing the design patterns of well-known architects (e.g. Palladio, Frank Lloyd-Wright).These examples demonstrated that complex geometrical shapes could be generated by a set of replacement rules out of a start symbol, usually a simple geometric shape. With the advent of powerful tools like the CityEngine an interesting field for practical applications of these grammars arose opening a whole range of new possibilities for architectural heritage.On the one hand, a description of ancient building principles in the formalized way of a shape grammar can aid the understanding and preservation of cultural heritage. With the possibility to actually construct digital 3D models out of shape grammars, they became even more interesting. Furthermore, this approach allows for a large scale creation of 3D models of entire settlements and cities.On the other hand, shape grammars allow for structured approaches to virtual 3D reconstruction as has been demonstrated for e.g. Mayan or Roman architecture. Besides that, the possibility to specify parameterized variations of the models proves to be an extremely helpful feature.In this paper we reconsider shape grammars in architecture and examine influences onto procedural modelling. Then we argue for state-of-the-art tools like the CityEngine that apply shape grammars and procedural modelling in architectural contexts and exemplify their power and potential by reconstructing traditional Balinese settlements