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This project contains the data and created scripts that are used in the article "Representing Geometries in a Semantic Web Context".

Collaborative built heritage projects require that a large variety of stakeholders, often using different tools and datasets, collaborate efficiently to conserve a valuable heritage building. Despite the opportunities of a thorough digitization, the general adoption and exchange of structured data during such projects is currently lower compared to other sectors of the construction domain focusing on new buildings. Besides conventional Building Information Modeling (BIM) applications and related exchange formats such as IFC (Industry Foundation Classes), researchers have been studying the potential of standardized Semantic Web Technologies (SWT), including Linked Data graphs, to improve the modeling of structured building data and its exchange over the Web. In this thesis, it is argued that the (Heritage) BIM concept can be implemented using SWT, resulting in a framework for a Linked Data-based Heritage BIM (LD-based HBIM), instead of relying on conventional BIM technology alone. The application of SWT requires the availability of a shared data structure, documented in so-called web ontologies, to obtain rich and interoperable building descriptions. A network of modular ontologies is proposed in contrast to a few large and complex ontologies. In many cases, terminology documented in these modular ontologies is expected to be applicable beyond the heritage domain, e.g. for the description of new buildings or other types of constructions. Besides ontologies, workflows and proof-of-concept applications are considered valuable to demonstrate how the LD-based HBIM framework can be applied in practice. First, the characteristics and application of SWT in built heritage projects, besides other data technologies, are studied through a literature review. Second, current workflows in the Flemish built heritage sector and opportunities for digitization are collected through semi-structured interviews with stakeholders. The results of this stakeholder analysis are used to derive five thematic sets of requirements - including overall needs and requirements related to the description of buildings in general, geometry, damage and construction dataset metadata - as the benchmark for the development of the LD-based HBIM framework. Using the benchmark requirements, an ontology network is prepared consisting of existing, transformed and, wherever necessary, new ontologies. In the proposed ontology network, a division is made between (1) concise core ontologies for the description of buildings and related aspects, (2) extending ontologies and taxonomies for properties, geometry metadata and classification, and (3) a separate set of terminology for construction dataset metadata. According to best practices, existing ontologies such as BOT (building topology) and DCAT (general dataset metadata) are reused wherever possible. The OMG (geometry linking), OPM (properties versioning) and DOT (damage linking and topology) ontologies are newly developed together with other researchers. The new CTO (construction tasks), ConTax (taxonomies management) and CDC (construction dataset context) ontologies are a direct result of this research. Existing taxonomies related to the classification of construction components, spatial building zones and materials are transformed to make them suitable for application with the core ontologies. In addition, new taxonomies are prepared for properties (CP and BHP), geometry formats (FOG) and the classification of damages (MDCS-O and MWV-D) and tasks (MVW-T). Finally, the new GOM ontology can be combined with OMG and FOG to facilitate the reuse of geometry descriptions in any existing geometry format. Different workflows, accompanied by existing and newly developed demo applications, for the authoring of building datasets are identified and analyzed. The modeling of construction dataset metadata and the exchange of datasets are documented in a higher-level workflow. The developed ontology network is applied in five example cases, inspired by two built heritage projects in Ghent, to demonstrate the new functionalities of the developed LD-based HBIM framework. The developed ontology network proves valuable for the description of unique and potentially complex heritage buildings thanks to its modularity, concise core ontologies and extendable taxonomies for classification and properties. A large part of the developed ontologies can be reused to describe other types of constructions. The thesis demonstrates how technical and semantic interoperability can be established by applying the LD-based HBIM framework while creating, exchanging and reusing construction datasets. status: published

The Damage Topology Ontology (DOT) is presented, a web ontology that provides terminology to represent construction-related damages and their topology as well as relations to affected construction elements and spatial zones. Besides the topology, classes and properties for documentation management and a minimal structural assessment have been proposed in DOT. In this regard, DOT provides all classes and properties needed for practical use in construction inspections and damage assessment. The ontology is developed to be used with the modular Linked Building Data ontologies structure, where DOT works as core damage ontology which can be extended with multiple modules related to detailed damage classification, damage assessment, mechanical degradation and other application scenarios. Geometrical damage representations are separated from the topology, so that it is possible to initially record damages during the inspection without any geometrical properties and link it later with a corresponding representation using terminology from geometry-related ontologies. In conclusion, DOT can be applied as a stand-alone web ontology to represent damages in a machine-interpretable format and replace conventional record approaches. Therefore, a generic terminology is used that enables the inclusion of various types of damage, which can be extended with domain-specific information. ispartof: pages:64-77 ispartof: CEUR Workshop Proceedings vol:2389 issue:6 pages:64-77 ispartof: Linked Data in Architecture and Construction (LDAC 2019) location:Lisbon, Portugal date:19 Jun - 21 Jun 2019 status: Published online

Several methods for creating building-related Linked Data graphs exist. This paper focuses on the conversion of IFC Building Information Models (BIM) to RDF Abox graphs using the emerging W3C Linked Building Data (LBD) modular ontologies: BOT (building topology), PRODUCT (classification of building elements) and PROPS (building-related properties). The existing IFC-to-RDF converter tool, converts IFC into ifcOWL-based Abox graphs which are rather complex and difficult to implement in software applications. The IFC-to-LBD converter presented, is necessary to transform IFC building models into RDF Abox graphs structured according the new LBD ontologies. An output graph contains the relevant information of the IFC building model related to building topology, building elements classification and building-related properties. Additionally, the graph structure becomes more concise (minimum 83 % less triples) and significantly easier to query compared to the output of the ifcOWL-based IFC-to-RDF converter. ispartof: pages:34-43 ispartof: Proceedings of the 6th Linked Data in Architecture and Construction Workshop (LDAC 2018) vol:2159 pages:34-43 ispartof: 6th Linked Data in Architecture and Construction Workshop location:London, UK date:19 Jun - 21 Jun 2018 status: Published online