As the barrier is going to be attached in my lot space, do l actually need her permission to proceed?
Are the garages common property or lot property? That could make a considerable difference.
In any case, she’s the one breaching the rules. If she wants to get snitty about it, just tell her if she wants to go by the letter of the law, she can get all her rubbish out of the car space and stop parking in visitor spots.
I don’t see the point of the wire netting on either side, to be honest. If it’s loose enough to allow opening of doors, what purpose does it serve? Also, parking spaces are designed to allow car doors to be opened, even if it means they have to swing slightly into the adjoining space. If her boxes prevent you from doing thi, she should be told to move them.
Obviously in such a small scheme, disputes like this can get very personal – but that doesn’t mean you should let bullies rule the roost. Perhaps what you should do is show her your plans as a courtesy but make it clear they are not dependent on her giving permission.
And if she does get high and mighty about it, apply for mediation at Fair Trading with a view to getting her to remove the boxes and stop parking in visitor spots.