The exact distance between layout lines. 
   Namespace:   Autodesk.Revit.DB  
  Assembly:   RevitAPI  (in RevitAPI.dll) Version: 2015.0.0.0 (2015.0.0.0) 
Syntax
Remarks
 This property is only available when  Layout  is equal to FixedDistance, MaximumSpacing, or MinimumSpacing. Must be a positive value less than 30000'. 
 Exceptions
| Exception | Condition | 
|---|---|
| Autodesk.Revit.Exceptions InvalidOperationException | Thrown when the Layout property is None or FixedNumber. |