I view this as an inflation adjusted income stream. 5.

You'll also want to ask about other fire and safety related improvements you'll be required to make to the property if the municipality considers it a "multi-family dwelling". 

I'm interested in developing a passive income stream over the next few years with single family homes.

Rooms or Units in dwellings containing living quarters occupied or intended to be occupied by no more than four families living independently of each other, if the owner actually maintains and occupies one of such living quarters as his residence"that is a sub-sectionin other words if you lived in the house, there can only be 3 other non family members renting, but if you don,t live there, you can have 4 non-related individuals in there. 

That should give you pause.On the expenses, water is not 4x a SFR for a four plex - more like probably 2-2.5x because there's generally less landscaping per resident and the occupants per dwelling unit is generally less in an apt.And, your trash is way low.

Number one is don't dwell on the past.  

In DC you can add accessory dwellings in the basement like @Russell Brazil said but there are requirements. 

Now, my BURNING PASSION is to:-revitalize this area with rehabbed properties that add value to this great community-Specialize in rehab and multi-unit dwellings (flip as well as hold)-Do the work of MINISTRY by creating training opportunities for the disadvantaged and the unemployed to work on properties doing demo/clean-up/trade learning. 

Even the larger companies should stick to this basic process and make sure that the company fixes any communication flaw as soon as they become aware of it.There are many other aspects that the company can dwell on; however, if they stick to the basics keeping with the example of communication, they can trump a majority of their competition since their competition is more worried about growing exponentially and leaving all their true customers in the dust. 

Once we maintain a good solid income stream from our first I'm hoping in 2 years to move on and purchase a second multi-plex and do the same.