B1
in the next room, house, or building
Dictionary examples:
My neighbor next door practices yodeling at 3 AM every night. (0.0)
I can smell the delicious pizza from next door. Too bad I'm on a diet! (0.0)
My neighbor next door is learning to play the bagpipes. Help me! (0.0)
That's the old man who lives next door to Paul. (30.1)