4-plex House Hack: How much and when do I tell the tenants?

[Justine Scheuher]

I'm purchasing a 4plex. My goal is to move into one unit, fix it up, rent it out....and then repeat with other units as the current tenants leases are up. The first lease isn't up until March 2020. As long as they are good tenants, I would offer them the fixed up unit (that will probably be $250 more than their current rent), but if not..I wouldn't renew their lease. 

In the meantime, I am planning on raising the rents on all units as their leases are renewed (only by $50). My reasoning is because they are currently under market value and initially I will be doing some upkeep on the deferred maintenance of the house, putting in a security system, and cleaning up the common areas. 

How much and when do I tell the tenants?  Thanks!