Mass from two toposurface

Hi all, i’m trying to understand the way to define a mass on the base of toposurface intersection, i have one topo defined the pre-construction state and a topo rapresenting the excavation, i need to extract the mass of the difference. Could someone put me in the right way?
thanks

Hi @paolo.campana, what object is “toposurface” exactly and in what software? If you have any Dynamo graphs you’ve created so far, please attach them.

Sorry…i forgot…software is revit…

What is the version of Revit? And surfaces are topography objects?

Revit 2023, surface are topography