Shades of gray.
Eye of the beholder.
Debatable technicalities.
If I were in this discussion I would not see the need to establish hard lines or over rule some opinions based on these items.

Builders don’t really build houses, tradesmen do.Owner builder’s also rarely do a very high percentage of the actual work but like to think they did.

Anyway, here is an example of what I mean that is close to home; Many of you know that I designed, drew the plans for and OVER built my own house on a carved out hill on wild lands. Me and my better half anyway. I did most of the physical work too.

With stock Milgard vinyl windows, a rather plain facade and a few interesting things but no really extraordinary features. I can call it a custom house by all the definitions mentioned in this thread but it seems like and exageration…doesn’t sit right with me. I guess I would call it an owner built, somewhat customized, overbuilt country suburb, tract home. So like I said, no sense splitting hairs or trying to have the final word.

I think the remodels are “customized” tract homes. .