Several tasks in urban and architectural design are today undertaken in a geospatial context. Building Information Models (BIM) and geospatial technologies offer 3D data models that provide information about buildings and the surrounding environment. The Industry Foundation Classes (IFC) and CityGML are today the two most prominent semantic models for representation of BIM and geospatial models respectively. CityGML has emerged as a standard for modeling city models while IFC has been developed as a reference model for building objects and sites. Current CAD and geospatial software provide tools that allow the conversion of information from one format to the other. These tools are however fairly limited in their capabilities, often resulting in data and information losses in the transformations. This paper describes a new approach for data integration based on a unified building model (UBM) which encapsulates both the CityGML and IFC models, thus avoiding translations between the models and loss of information. To build the UBM, all classes and related concepts were initially collected from both models, overlapping concepts were merged, new objects were created to ensure the capturing of both indoor and outdoor objects, and finally, spatial relationships between the objects were redefined. Unified Modeling Language (UML) notations were used for representing its objects and relationships between them. There are two use-case scenarios, both set in a hospital: “evacuation” and “allocating spaces for patient wards” were developed to validate and test the proposed UBM data model. Based on these two scenarios, four validation queries were defined in order to validate the appropriateness of the proposed unified building model. It has been validated, through the case scenarios and four queries, that the UBM being developed is able to integrate CityGML data as well as IFC data in an apparently seamless way. Constraints and enrichment functions are used for populating empty database tables and fields. The motivation scenarios also show the needs and benefits of having an integrated approach to the modeling of indoor and outdoor spatial features.

The integration of Building Information Modeling (BIM) and Geographic Information Systems (GIS) is increasingly critical for infrastructure planning, asset management, and smart city applications. While prior efforts have largely focused on buildings, the need for semantically rich, interoperable models for roads and transportation networks is becoming more prominent. This paper investigates the potential for unidirectional conversion between IFC 4.3-based road models and the Transportation model of CityGML 3.0. Through manual schema matching, the study classifies correspondences into full, partial, or no match categories and assesses the potential for semantic and geometric translation between the two domains. Findings reveal that while basic spatial and geometric entities can be mapped with partial fidelity, significant semantic details such as alignment geometry, layered road structures, and road furniture remain unmapped. The paper concludes by recommending the development of a unified road ontology or mediation layer to support lossless integration. These insights contribute to ongoing efforts in GeoBIM interoperability, such as those led by buildingSMART International and the OGC's CityGML working groups.

Building information modeling (BIM) and geographic information systems (GISs) are increasingly integrated to meet modern infrastructure demands. A key challenge is the lack of interoperability between the Industry Foundation Classes road model used in BIM and the CityGML transportation model used in GIS. This study presents the unified road model, a framework for bidirectional interoperability by aligning semantic definitions, geometric representations, and attribute mappings to preserve engineering and geospatial data. The unified road model combines volumetric data from the Industry Foundation Classes with CityGML's multiple levels of detail and was validated through a signalized intersection and a roundabout in the Örebro–Karlskoga corridor in Sweden. Results show the unified road model connects data from both domains, maintaining attributes such as material properties, alignment geometry, and spatial relationships. This demonstrates its potential to enhance multidisciplinary workflows, reduce data loss, and improve BIM–GIS collaboration. The study recommends further research into automation, scalability, and smart city applications.

COVID-19 pandemic has spread rapidly affecting the entire world. During the fight against the pandemic, hospitals are insufficient to meet the needs. This study aims to set the basis for optimal site selection of quarantine hospitals. Further, to determine the critical factors influencing this selection. The Dual Level Location Suitability Index (DLLSI) proposed methodology provides decision maker with the optimal city and the optimal sites in the selected city for hospital construction. Analytical Hierarchy Process approach is implemented as a part of this study with 14 criteria used to evaluate the alternatives. Safety, accessibility, and availability criteria are also influencing the site selection. The results of DLLSI proposed methodology implementation show the optimal city and the optimal potential sites. It is observed that potential optimal sites located in optimal city. This is considered as self-evaluation, one of the contributions for the proposed methodology. Furthermore, the results of the proposed model are robust, realistic, and supportive for decision makers.