Sorry, I can't hold back. I'll repeat myself:

If you build something from scratch that means you have drawn a set of plans or construction drawings to allow you to build the model.

If you obtain a set of plans or construction drawings from other sources to help with the build of the model, that is a plans-built project.

This is not my idea nor anything new, but something I was exposed to some 55 years ago when I started building flying models.

Bob