Spring stiffness calculation

[bricksandmortar]

Hi,

I am not a geotechnical engineer but have a question about the parameters required to calculate a spring stiffness for soil/structure interaction.

If I am looking at a site where an existing building with a basement is going to be demolished and replaced with a new taller building including a 1m deeper basement, are the proposed loads only required for calculating spring stiffness / settlement / heave etc. or are existing loads and proposed loads required?

Are existing and proposed required for ground movement analysis?

Thanks,