Should I cut buildings from flood zone? At work (at a local authority), I have a flood zone plan/layer that was created using ArcGIS software from an Elevation Model which has an accuracy of 1 metre. The zone covers an urban area. I cannot get to the resolution of which buildings will be more effected by flood and which won't, but I do have a layer of all buildings.

The question is, whether I should cut the buildings out of the flood zone, and why?
Since it is not known at this stage what measures were implemented for each building in regard with eventual flood situations, it does not make sense to purposely exclude the buildings from the flood zone until some kind of general database with that info is built and put into context in your system. Even-more, a lot could happen in a potential flood zone when an extreme event occurs, regardless of the prevention plan by various owners and city management. A risk management model with proper risk probabilities, potential damages and monetary values would eventually be required to better represent the up-to-date context of the site.