Hi howdoiknowthisinfo,
You might have noticed on the drawing below, that we have a reference on each point of interest. All you must do is ask me for the ref. no and I will be glad to provide it to you. So, you want to know the source of the floor levels which are ref 921, ref 386 and ref 691. They have been provided by Land ID in form of a Topographical KML map. See below reference document.
May I ask you which source you are using for your floor levels?
