So let’s assume with realistic expense estimates over 1st 5 years you average $250 in today equivalent dollars (it will be a challenge at that starting point).The ADUs are typically receiving valuations below $100k, but let’s be generous to show the scope of the people and say it adds $150k of value. 

@Shayan Sameer If you can service all debt and property expenses and have money left over then I'd say it's worth it.

The place I have is over 30 years old and a mansion ("mansion" in Japan means an apartment, not "mansion" like a huge house). 

The 23 doors are only spread over 4 properties.

But, these broad market studies are so large, they are almost meaningless, in the real world.Between glut of new supply in many "hot" markets coming online, a continually softening economic outlook, inflation over last couple years making day to day items feel cost prohibitive, many average renters are strapped and seeking lower cost housing.  

I would spend time building your list of WHO (agent, mentor, contractor/handyman), then WHAT (house type, tenant base, work needed), then WHERE (location).

Ensuring your rental market can sustain these costs will help maintain profitability over time.The 7% DSCR loan is relatively high, and refinancing later at a lower rate could improve your long-term cash flow.

There's a 38 unit fully renovated likely willing to sell at over a 7 cap.

If you can afford a higher payment, a 15-year mortgage saves on interest over time.For the down payment, aim for at least 5%, but if you can put down 10-20%, you'll avoid PMI and could get a better rate.

I know when it comes to many cities there are long permit processes and also there are specific air laws that go into each city.I would love to hear a story that goes over an experience pertaining to developing/rehabbing a property in the DC area.