Cutout parametric holes into breps

Hello everyone!
We are trying to cut holes into a given brep. We wraped parametric squares around a solid tower but can´t cut holes into the surface. Would be great if someone could habe a look into our gh script.
Thank you, Harald


Forum_Kletterhalle.gh (13.7 KB)
Forum_Klettterhalle.3dm (2.4 MB)