Multifamily Condo Building Age

[Chassidy Hammond]

My first post at BP...currently educating myself on multifamily rental properties. Considering a listing of 5 condo units. These units have recently been renovated interiorly, but I believe the original structure was built in 70s. My question is, what age multifamily structure would you shy away from? If I’m wanting to hold and rent for a while, is there a rule of thumb for structure age I should factor into my exit strategy?