The fix-n-flip part should be pretty easy and, provided you can document a couple of ground up deals, we can likely help, but that equity component will be a challege for someone like us. 

I need to do some more digging but great to have your contact once I define a location.  

In general there definitely sounds like there would be some difficult components of trying to do any type of expansion for the existing coach house and again, RT-4 does not mean you are permitted to have 4 Units (unless you have a 4000 sq.ft. lot or larger).

This will work no matter what, but you can get there faster if you can generate equity through remodel, take advantage of market shifts or buy at a discount (next to impossible at the moment due to tight inventory, but that may come back).The other component most new investors underestimate is you have to become an excellent operator.

., I like how @John Karg is tossing the Internal Rate of Return components at you so you can get a true perspective of how that house is performing and can perform. 

Define your "buy box" or criteria for your first property (this may change a bit as your start analyzing deals and looking at properties, but it's important to know what you want). 3.

Adequate risk management strategies are essential to mitigate financial risks.Property Performance: Maintaining a healthy DSCR ratio requires diligent management of the property to ensure consistent income generation and control operating expenses.In conclusion, DSCR loans are a vital component of commercial real estate financing, offering both opportunities and challenges for borrowers and lenders.

And it's ability to let you take advantage of all of the components of the IRR to maximize your return. 

I'd say the critical component to securing a worthwhile multi family investment (and any real estate for that matter) is timing.

However, you should explore whether any exceptions apply to your case, such as unforeseen circumstances.Unforeseen circumstances, as defined by the IRS, might include changes in employment, health issues, or other unforeseen events.