Typically those are built with 4 units to an overall structure. 

Quote from @Jenni Utz: You have that built-in equity on the deals that are off-market.

I for one built a simple chrome extension to see if the mortgage is less than rent and accordingly provide that information on every zillow listing page.

I plan for a time when they can be there and check in and make sure there aren't any maintenance items they haven't told me about.

I own a single-family home built in 1950 here that I rent out.

They've built a second campus to accommodate nursing and pharmacy students. 

I'm sure HUD put a specific line item (503) on the settlement statement to help people commit fraud... wtfhttps://www.hud.gov/sites/documents/1.PDF

Built in security as I don't visit the land much as I am in Connecticut.

Built in property managent.

The good thing about bonus depreciation is that you can take the amount eligible for bonus depreciation in that given year.For example - if you place a $50,000 item under 5 Years MACRS on December 31st, it would be eligible for bonus depreciation which as of right is now 60%.