Solar envelope volume/generating the building form

Hi,

I am working on the attached file for generating a solar envelope volume in a generic setting. I am stuck at generating the enclosed form of the solar envelope. I have used ‘solid difference’ and ‘trim solid’ but could not get the desired building form. I would appreciate your advice regarding this.
Thanks.
JH

Solar Envelope Enclosed Volume - 24 July 2020.gh (411.2 KB)