You can prevent an element from appearing in the project estimate by changing a setting on the element’s Quantity property page.
To prevent an element from appearing in a project estimate:
Select the element in your drawing.
Right-click and select Properties.
In the properties dialog, select the Quantity tab.
Disable the Include Element in Quantities check box.
Click OK.
Note: You can also apply this change to elements in the catalog. The change will affect all new insertions of the element.