I have been playing around with my local copy of sweethome3d to add support for walls with a sloping base.

I have found this much easier than creating invisible windows to cutout the base of the wall. The window technique can be seen in images 43/44 here https://www.sweethome3d.com/support/for ... ,yes#61532

This can be useful for dormers and such.

I have a working (I think) patch. Is this a behavior that there would be interest in adding to the base application.

Also, I don't see any FAQ for contributions, so: is there any contribution process?

Lastly, I am willing to work with my code to fit it within whatever guidelines are necessary.