City 3D-model - Supporting Sustainable City Development

The city model of Espoo is a constantly evolving 3D model, that follows the OGC CityGML 2.0 standard. CityGML (Geography Markup Language) is an open data model for the storage and exchange of virtual 3D city models. The aim of standardised models, such as the open data CityGML model, is to allow the same data to be reused in different application fields. 

While CityGML represents the graphical appearance of city models, it also addresses the representation of the semantic and thematic properties, taxonomies and aggregations. CityGML not only includes a geometry model but also a thematic model, which employs the geometry model for different thematic fields. Additionally, Espoo uses generic objects to visualise mainly underground infrastructure, such as pipes, wells, and heat pipes. Engineering structures (such as bridges and tunnels) are currently not covered by the model.

Information about the actual built environment of Espoo are presented in the city information model (CIM), which is maintained in Trimble Locus, a geographical information database. The model serves as an initial information model and enables more efficient planning and decision-making. The model contains information of about 64 000 buildings, bridges, streets, city furniture, etc., and is updated by the city survey department.

The further development of the 3D model will provide an even more comprehensive tool for city architects but also for citizens (e.g., by integrating more data and climate protection indicators). The visualisation of energy data in a 3D model can help to support energy efficiency improvements, energy consumption minimisation and renewable energy. The data available in the model can also be used for simulations of thermal energy demands and energy balance modelling.