I'm planning Ann extension to my 50s house and considering the corridor next to the stairs.
I think it's too narrow at 800mm.
Victorian houses have narrow corridors, but how narrow? I'm guessing similar based on a 6 foot space for hall and staircase.
Current building regs are 900mm in England.
I'm leaning toward moving my existing wall to make the corridor wider. That'll make a loo under the stairs access less cramped too.