## 5.2 IfcControlExtension

### 5.2.1 Schema Definition

The IfcControlExtension schema in the core layer declares basic classes for control objects (IfcControl, IfcPerformanceHistory) and assignment of these (IfcRelAssignsToControl) to any object derived from IfcObjectDefinition. Also, it declares the classes to associate resource level objects of controlling nature to any subtype of IfcRoot, using IfcRelAssociatesConstraint and IfcRelAssociatesApproval.

> HISTORY New schema in IFC2.0.