The issue is confusing to me. That's what I heard from natives.
1 The house has a door at either end.
2 The house has a door at both ends.
Some say that 1 and 2 are correct and mean that there are two doors, one door at each end.
Others say that 1 doesn't mean that there are two doors. It means that there is only one door at either end.
Others say that 2 is incorrect because it's impossible to have one door at both ends. Probably, they meant it that way if we use "one door" instead of "a door". Would this make a difference?
3 The house has ONE door at both ends.
Do 2 and 3 mean the same or not?
Others say that the best is this:
4 The house has a door at each end.
What are your ideas, comments on the issues?