Is there a function to compare two map layers to create a new layer. For example, both map layers have roads and buildings on them. The old map layer contains buildings that no longer exist and the new layer contains new buildings in exactly the same place. When you have both map layers on, the buildings overlap. (The function could therefore look at the new things that are on the newer layer.) Is there a function that 'automatically' wipes away the 'piece of land' that is under the new building? (White polygon or...).