Many times it happens that we have a slab and/or roof in which we want to subtract one or more areas, and although we can do it through the Pet palette that doesn’t always work in the most effective way since for each area we want to subtract we must click again on a node which makes the process much slower. But… What if I told you that it’s not necessary to do that? And it’s that Archicad has an option that if we select the slab or roof tool while we have selected any of these elements in the model, it will subtract the area that we draw on these. In this way we can make more subtractions more efficiently.