Represents a phase in the life of a building. 
   Namespace:   Autodesk.Revit.DB  
  Assembly:   RevitAPI  (in RevitAPI.dll) Version: 2015.0.0.0 (2015.0.0.0) 
Syntax
Remarks
 The lifetime of an element within a building can be controlled by using phases. Each element will have a construction phase but only those elements that have a finite lifetime will have a destruction phase. All the phases within a project can be retrieved from the Document object.