Only as a side note, while small drones won't be an issue, eVTOL are in a weight range that even as a static load (i.e. not even considering dynamic effects of

Only as a side note, while small drones won't be an issue, eVTOL are in a weight range that even as a static load (i.e. not even considering dynamic effects of landing in a less than perfectly "soft" way) are likely well over the specification of a "normal" flat roof of a building. To this you add that you need to provide a way for the operators and passengers to reach and leave the roof (and this in many buildings would imply a dedicated staircase/entrance). The terrace of a multi-storey parking garage might do.