How do I create an irregular hollow solid. (New to Rhino)

This building was first created in sketchup with planes of no thickness. I then imported it to rhino but how do I create thickness for the wall correctly so that it wouldn’t end up like the image below where the edges are not joined.

Or if I were to design the building in Rhino from scratch, what will be the ideal tools and steps as it is a complicated and irregular solid.

Have you tried joining the planes first (option “Solid” activated),

and then use OffsetSrf:


If the arrows show the wrong direction, use “Flip All”.

Thank you for the tip. I have joined the planes together and managed to offset it by using offsetmesh because srf did not work.

Sorry for that.
It wasn’t visible if you had meshes.

It´s always nice to have regular N.U.R.B.S. objects (Non-Uniform Rational B-Splines, if I´m correct on that).
To get there if you imported meshes from SketchUp, you could use “MeshToNURB” and do the other steps afterwards.

just my 2 cents …