Just an update note, the documentation is clear but I'm having to admit there's not enough available time to complete the project.

Because walls are placed on center and wall thickness varies, my original vision was to design a spreadsheet that would take care of the offset math and allow the user ...

Thanks, great community here. And thanks for the guidance; here's what I've found:

Success opening the plain .xml, but only when 'image=' value matches the spec on the default catalog page you linked. Ex. "/com/eteks/sweethome3d/io/resources/textures/smallRedBricks.jpg"

Important to note: The ...

Exactly the info I was seeking and works great... except for textures! Once added to an open file, textures are saved in Home.xml (of the .sh3d zip) perfectly. But the program seems unable to find even its own textures and refuses to open any xml that contains one.

Is there a trick to make this ...