I am often reminded that even simple tools can make a huge difference when completing a takeoff with Autodesk Quantity Takeoff (QTO). The Backout (subtraction) tool is no exception to this. I was with a customer recently and was not only reminded why this is a fun little tool, but that it might have another use as well.
Polyline Backout:Allows for multiple points (lines and arcs) in the backout
Rectangle Backout:Creates and rectangle shape backout
Ellipse Backout:Creates and ellipses shape backout
Count Backout: Acts as a subtraction tool to delete count items from the takeoff
Using for Area Backout:
The Area backout tools are great for when you have an area that covers a portion of your takeoff where you need to perform a subtraction. See below images (Figure 1) for more info.
Figure 1: Image above shows backout tool removing area takeoff over column
Using for Linear Line Break:
As a good alternate use, the backout tool can also be used to "break" linear takeoffs. Take the example shown below. The takeoff was complete with a single line segment through a door, but maybe you have a workflow where you don't complete takeoffs that way. You could use backout tools (except count backout) to remove that portion of the Linear Takeoff that is in the door. See Figure 2.
Figure 2: Image above shows backout tool deleting line segment at the door