Let’s go low-level today:
In this topic I would like to give a very simple hint on the use of Parts in a model. When creating a Multi-category Material TakeOff in Revit, the schedule also takes into account the parts that are made from i.e. walls or floors. That means that if you don’t pay attention when using Parts, the material volumes are considered for walls and their derived parts!
If you don’t want the Parts in your MTO (for no matter what reason), you can use the “Category” parameter in your Material TakeOff and put a filter on it to exclude the Parts category from your schedule. (Optionally, hide the “Category” parameter in the formatting tab).