Smart Data Models’ Candidates repository now includes a new candidate standard translated from RealEstateCore (REC): realestatecore, with 10 candidate models for real estate and smart buildings. REC is published under BSD-3-Clause. Like every candidate, each model comes with a JSON Schema, an NGSI-LD @context and all four example serializations (NGSI-v2 and NGSI-LD, key-values and normalized), each validated against its schema.
About RealEstateCore
RealEstateCore is an ontology for the real estate industry, maintained by the RealEstateCore Consortium. It describes the spatial hierarchy of property (sites, buildings, levels, rooms, zones), building elements, the assets placed in buildings, administrative groupings such as portfolios and premises, organizations, and events such as leases. Since version 4, REC is co-designed with Brick Schema: Brick provides the equipment and sensor-point taxonomy, and REC provides the real estate and location layer. This translation uses release v4.1.0 (June 2026).
The models
| Model | Types in recClass |
Examples |
|---|---|---|
Site |
– | a parcel of land |
Building |
6 | Building, Hospital, School, ShoppingMall, Stadium |
Level |
4 | Level, BasementLevel, MezzanineLevel, RoofLevel |
Room |
95 | Office, ConferenceRoom, CookingRoom, Bedroom, Lobby, OperatingRoom |
Zone |
6 | HVACZone, OccupancyZone, AccessControlZone, ParkingSpace, Workspace |
Asset |
61 | Desk, Chair, Door, Window, IAQSensorEquipment, NetworkRouter |
Collection |
8 | Apartment, Campus, Portfolio, Premises, RealEstate |
BuildingElement |
7 | Facade, Wall, Slab, Roof, Balcony |
Organization |
3 | Organization, Company, Department |
Lease |
– | a lease of a building, premises or asset |
The models are connected through REC’s own relationships: spaces hasPart and isPartOf each other, assets are locatedIn spaces and hasPoint their Brick sensor points, collections includes their members, and leases link leaseOf, leasee and leasor. In NGSI-LD these become Relationships.
Brick and REC, together in the Candidates repository
The examples come from the same real deployment as the existing Brick Schema candidate: Brick’s own indoor air quality example, a single-family home at 123 Alder Street. REC describes the site, the building (with its address and 165 m² gross area), the first floor, the kitchen, the whole-home HVAC zone and the kitchen’s sensor device. The device’s hasPoint links point straight to the Brick candidate’s CO2, PM2.5, PM10, humidity and occupancy sensors. In the same update, the Brick candidate’s examples now point to these REC rooms and zones instead of placeholder location IDs, so the two candidates form one connected graph.
Translation notes
- REC 4.1 from its DTDL source. REC is published as both SHACL and DTDL, but in v4.1.0 only the DTDL contains the 4.1 additions (Warranty, asset
colour,memberOf, and the Lobby, Lounge and Team room types). The DTDL is used as the source, and SHACL supplies cardinalities and datatypes. - Names preserved verbatim. REC’s class and property names are kept exactly as REC writes them, including
IPAddressandMACAddress. - One model per branch. Rather than 95 separate room types,
Room(like Building, Zone, Asset and others) carries the specific REC class inrecClass, restricted to the non-deprecated classes of that branch. Brick’s own equipment classes stay with the Brick candidate. - Simplified structures. REC’s GeoJSON geometry maps to the NGSI-LD
locationattribute. Postal address, area and capacity are inlined as structured properties that keep REC’s field names. - Licence verified. REC is BSD-3-Clause, the same licence as Brick Schema.
Try it, and tell us what’s missing
These are Candidates: first, carefully sourced translations that are not yet official Smart Data Models subjects. Before that step, the main open question is overlap with existing models, especially dataModel.Building, dataModel.Organization, the S4BLDG subject and the SAREF4CITY candidate. Natural next steps are Region, Person, Warranty and REC’s observation events.
Browse the models, open an issue, or send a PR:
👉 https://github.com/smart-data-models/Candidates/tree/master/standards/realestatecore
