- Metadata – Various annotation properties used to document the entire ontology suite.
- Units – Datatypes, measurement units, and quanity kinds used in RealEstateCore (a subset of QUDT)
- Core – Collects the top-level classes and properties that span over or are reused within multiple REC modules. Imports the Metadata and Units modules, and is imported by all other specific child modules.
- Addessing – The addressing module; message semantics for requesting and enacting actuation on building systems.
- Actuation – The actuation model; message semantics for requesting and enacting actuation on building systems.
- Agents – Basic types of agents (people, organizations, companies, departments).
- Analytics – A vocabulary for describing prognoses and aggregates, and the processes used to generate these.
- Asset – An extensive categorisation of assets within buildings, e.g., equipment, systems, furniture, architectural/installed assets, etc.
- Building – Different types of building components and rooms.
- Business – Covers leases and lease contracts, business roles, etc.
- Data schemas – Primitive and complex (object/array) data schemas for sensors, actuators, services, etc.
- Device – Device types (sensors and actuators), device configuration, device actuation, etc.
- LFR – Optional module covering the data model used by the Swedish National Land Survey, in its database Swedish Real Property Register (Lantmäteriets Fastighetsregister). Not included in the Full ontology below.
- REC Full – Imports all REC modules, providing the fullest possible expressivity.