As long as 75% of the rental income covers the mortgage payment (PITI), you are good.  

Also consider if the rents you charge would cover expenses if you were to live in one of the units.

@Yadira Gutierrez,Your manufacturer should have pictures of house modules being assembled inside their plant, being delivered to the site, put into place by cranes.

After looking at softwares and excel based on your recommendations, I decided to take on the challenge to create my own excel sheet that covers Income Statement, Schedule C, Estimated Taxes based on the current tax rates.

One municipality I invest in you need insurance that covers demolition in order to get an occupancy permit to rent the property.

The above pictured properties is one of mine that I'm doing this with!

Or I was also looking for 400k house that I would be able to add value such as guest house or something else to cover the mortgage payment?

How you would cover expenses with that scenario, I don't know.  

(Not by using Google maps because they can easily be outdated pictures) There should be some.

I noticed across literally across the street was a completely vacant house, with a boarded up front door and windows covered in blinds, shades, and newspapers.I did a quick parcel search in my county and found the owner lives not too too far away.