Buying a Multi without being able to see all units

[Jason Regan]

I am currently under contract on a 4 plex in Gardner Ma.  They are only allowing me to access about 50% of the units and the basement.  I know it is a older home and they sent me repairs needed per a section 8 inspection.  They also let me know the porch has to be redone ($18k) and electrical upgrades ($10k).  I budgeted $90k in renovation for this project to be safe.  I would love to know how people have come up with renovation budgets on rentals when they cannot see the whole house.  This is not vacant; three units have people living in them now.  No rent is flowing because section 8 cut it off until certain repairs are made

Thanks for your insight!