@Renata Johnson, okay...there's been a lot of other good advice offered so I'll offer a little more (but use their advice too).The whole "you have to have perfect credit and put 20% down to get a loan" is a flat out LIE. 

Depending on the state, that individual could have used a broker as a limited service agent and paid very small flat fee to an agent to put the property on the MLS.

Hello, Currently looking to purchase a multi unit 2-3 flat in Chicago.

All other residential buildings that are 20 years or older would be able to add 33 percent of the number of existing units, and rounding up or down.2-flats: 2x0.33 = 0.66 rounding up to 1 unit3-flats: 3x0.33 = 0.99 rounding up to 1 unit4-flats: 4x0.33 = 1.32 rounding down to 1 unit5-flats: 5x0.33 = 1.65 rounding up to 2 units6-flats: 6x0.33 = 1.98 rounding up to 2 unitsAnd so on.If adding a coach houseAll properties that are either vacant or have a single-family house, 2-flat, 3-flat, or 4-flat would be able to add one coach house as long as there is no conversion unit on the lot."

In a normal world, this would make all the sense in the world even with flat rents for a period of a few years!

@Terence D. below is a snap shot of a recent bill for a 2 flat. 

@James CarlsonThings to keep in mind: Breaker panel size.

@Michael Baum if you are doing flat pricing and not doing it dynamic you are leaving a ton on the table July 4th is worth more then July 7th for example.

If you don't have income, you shouldn't be borrowing money because you'll eventually fall flat on your face.

Have you looked at installing solar panels on your primary house and use the credit to offset what you could owe due to the cap gains?