It would be nice if the disable was part of the build button. The way this would work is when a mouse over of the build button occurs a menu would pop up with the option to build or disable the build.

When the build is disable a red circle with an slash through it would replace the build button and the build action would be disabled. A mouse over the disable button would give the options to enable the build or build once.

Doing the disable this way also cleans up the column real-estate; at the very least the current disable button should be made much smaller.