Very interesting! Is "tree-house building" a reference to something specific or did you make it up? It strikes me that engineering is either a spectrum, or it's a segment of a larger spectrum (the name of which I don't know). Tree-housing is near one end of that spectrum, the MacGyver end, and dam-building is near the other end (where the problem is thoroughly researched, the goals are calculated, and the designs are all made to serve those calculations specifically).

Do you feel "engineering" could cover the entire spectrum, where your "Engineering" specifies everything on one side of "has a design doc"? If not, is there a name for the whole spectrum? Does crocheting from a pattern sit anywhere on this spectrum, or is it something else, or does it mean that my spectrum-of-engineering is an illusion? Open questions here, not directed at DrNosferatu necessarily.