DHeselwood

I was just looking for this and the internet is awash with differing opinions so I went and found the answer. BS8541-2:2011 "Library Objects for architecture, engineering and construction (Part2: Recommended 2D symbols of building elements for use in building information modelling" states on page 28 (for windows, not doors although I would resume the same logic for doors applies) the arrow points towards the pivot point. i.e. image 2.