Repair of Lot Line Walls?

I'm looking at purchasing a property with a lot line wall abutting a maintenance alley owned by the apartment building next door. When this wall eventually deteriorates and needs to be repaired, what is the procedure for conducting the repairs, given that I will need access to their lot in order to do this? Presumably, I will need to get permission from the apartment building to erect scaffolding in the alleyway. Could this be a potential headache? Might they try to extract some kind of payment from me in return for the right to conduct repairs? Any advice would be very helpful. I'm a newbie to these these kind of issues.