Application and extension of 223P ontology for the district heating domain

Digitalization of district heating networks (DHNs) is vital for decarbonizing the heating sector, yet the lack of a standardized data model forces operators to build bespoke interfaces and impedes integration of new digital services. Existing ontologies such as OEO, CityGML and various DHN-specific models proved inadequate or poorly maintained for unambiguous DHN representation. We evaluated three interoperable building-domain ontologies—Bricks, 223P and Real Estate Core—and extended 223P to cover the unique information requirements of DHNs. In two case studies (SimKiMop and TrafoWärmenetze), the extended ontology successfully modeled network topology and heat-generation unit attributes for optimization and transformation planning. Using our extension and accompanying modeling guidelines, we generated interoperable RDF data graphs, enabled network visualization, and automated the creation and execution of optimization models. To ensure broad adoption, we are contributing this work to the IEA Annex TS9 framework, engaging municipal utilities via AGFW, and providing supporting tools and scripts for DHN model construction and validation.