@NikF I wasn't familiar with Placemaker until now.   Depending on where you are one can get similar data sets through GIS. Some of this is free and in other locations you have to pay. After you have determined the availability you can import legacy shape files and create and create a site model from the contours. With some extra knowledge of Marionette and some help from Vectorworks forum users you can create scripts that can query the data sets for building and assign buildings by use