I believe if you add square footage or improvements to your home, those improvements can add to your assessed value for property tax purposes:  What causes a supplemental bill?

Hello, Looking to replace/supplement coins for laundry payment.  

Indians would often survive on a simple diet of corn, beans and squash supplemented by protein from hunting kills.

If your hopes were to eventually have this property as supplemental income then I'd suggest selling it and buying a true investment property.

You have the option of supplementing that with your own evidence.

As pointed out most banks will have their own form of PFS that you can use but putting a balance sheet together and supplementing it with additional detail in my experience has never been a problem..

Cozy’s application isn’t currently customizable, although you could request supplemental information outside of Cozy as well.

Do you just want to supplement your full-time income?

My plan was to buy and hold them indefinitely for supplemental retirement income, but I have recently begun to think about selling one or two. 

Cash is the king and I need cash flow so I can supplement my income or retire at some point.