Create Solid between two surfaces

I am very stuck with the creation of a solid between two surfaces. I have a rectangle surface laying on the ground and a few joined patches flying above it. My wish would be to extrude the rectangle on the ground just up to the patch point above it.
I tried to calc the distance to the nearest point and extrude the ground rectangle but had no luck.

solid between (16.7 KB)

Any help would be appreciated.
Thank you

You can do this:

But you will have trouble making a “solid” from those curved patches on the roof because they overlap and don’t join into a single “Open Brep”.

This might be not what you want and the end result is slightly different from your expectation, anyway here’s an attempt with the help of the simple solution provided by @DanielPiker in this linked topic below…

solid between (11.9 KB)


Very nice, thank you very much!