How do I add a second USPS mailing address and still keep my first one?

It's complicated, but I have 2 houses, the one I inherited from my parents and the one I currently reside in. They are both in the same town. (I need to do renovations before I reclaim the parental homestead.) I originally gave up the mailbox at my new address, and have had all mail forwarded to my parents' mailbox, where I need to collect mail anyway. Not having a mailbox at my actual residence has resulted in some complications, so I am thinking of re-installing. How can I start up mail here again? All I can find online are "change of address" forms. I don't want to CHANGE address, I just want to add a second address. Any ideas?