Ridistribute volumes over a surface

Hi everybody!

I extruded the 3d city model of a city using a SHP file (you see here the baked version of it). My next step is to redistribute the volume of buildings over the whole building lot (the surface selected) and evaluate the density of the latter (volume/surface).
Model

The first thing to do would be evaluate whether the brep/building is over a surface/building lot or not, sum up the volumes of all the breps/buildings and extrude the surface/building lot of the consequent height. I can not however how to tackle the first step.

I attached the documents, thank you very much to whoever can help me!

Modelloe estrusione.gh (57.7 KB)

could you please internalize data inside this curve component?