- Metadata – Various annotation properties used to document the entire ontology suite.
- Core – Collects the top-level classes and properties that span over or are reused within multiple REC modules. Imports the Metadata module, and is imported by all other specific child modules.
- Actuation – The actuation model; message semantics for requesting and enacting actuation on building systems.
- Agents – Basic types of agents (people, organizations, groups), structurally aligned with FOAF.
- Analytics – A vocabulary for describing prognoses and aggregates, and the processes used to generate these.
- Building – Different types of building components and rooms.
- 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.
- Lease – Contracts, leasable premises, types of premises, etc.
- REC Full – Imports all REC modules, providing the fullest possible expressivity.