while the actual unit is most likely fairly heavy (especially with books in it), it should not feel as such...e.g. if properly set up it should swing very easily. why do I think this you say? because I've built more than a few such things and while I certainly needed help to carry and install, I certainly needed no such help when doing final adjustments and checking operation.  most likely the amount of force needed to overcome the latching system is far above what's needed to move the door after that point