title: Revit 2011 get the length of a wall
body: <p>Has anyone got any code to get the length of a wall?  Currently I use:</p>
  
  <pre><code>ElementCategoryFilter wallsFilter = 
    new ElementCategoryFilter(BuiltInCategory.OST_Walls);
  
  FilteredElementCollector collector = new FilteredElementCollector(Doc);
  IList&lt;Element&gt; walls =
    collector.WherePasses(wallsFilter).WhereElementIsNotElementType().ToElements();
  
  foreach (Element wall in walls)
    MessageBox.Show(wall.get_Parameter("Length").AsString());
  </code></pre>
  
  <p>Length comes back empty!!!</p>