Hi Marek, the type of mesh geometry you show there isn't suitable for sub-d smoothing. A mesh designed for sub-d smoothing should be made up primarily of quads and structured as described at https://www.youtube.com/watch?v=ckOTl2GcS-E .

What you have there is non-subd triangle mesh geometry, so it's not going to work right for using it as a sub-d control cage.

MoI is not designed to work with triangle mesh geometry like that.

If you can export from ArchiCad to .stl format you might try using an STL viewer type program such as https://www.materialise.com/en/software/minimagics , those are likely to have a weight calculator function.

- Michael

Hi Michael,

Thank you, as again your willingness to help is the most valuable add-on for MoI.
Yes, that software nicely imports the .stl model but that's it.
Now, it looks to me that the most efficient idea for this is simply to use Excel.

Thanks again,
Marek

There is another way to create a mesh with quads, from one made by triangles, using Blender, import your file in Blender and use the remesh modifier, and raise the level to nine and apply and then export a perfect mesh with quad topology.
below a try done now for this topic. but is bit heavy model, maybe reduce the subdivision with decimate modifier using option unsubdivide but with pair value multiply.

Tried that, but Blender (2.8) got inoperable after using Remesh modifier.
Nevertheless, there is a clever add-on in Blender - 3D Print Toolbox giving a Volume and an Area of solids, but I'm not sure about the accuracy of it in regards of real profiles thickness and so on.

Thank you, anyway