Modifying Vertical Offsets of Autodesk Revit Wall Components
by Peter Gehring
Link: Vertical offsets in walls
>This technique will show you how you can allow the components (layers) in Autodesk Revit Building's wall types to have adjustable grips to modify their vertical extents. These extensions can be constrained to the bottom of the wall or to reference planes or other geometry. By default all the wall components (layers) move together. This method will circumvent the default and allow you to show sheathing, siding, or stucco layers overlapping floor joists or foundation walls. It can also be used to vertically extend the top of the wall's assembly layers. When you select a wall in section you'll see a triangular blue grip at the top or bottom. Stretching this grip gives the wall an offset above or below its constrained level.<
Note: Towards the end of the article Peter talks about being unable to set distances while dragging. While this is true, you CAN use dimensions to control this through "base (or top) extension distance" in the element properties dialogue box.