However, to calculate my net gain, do I minus my down payment and closing costs from the $300,000? 

I will be self managing from San Diego and once all the units are turned over and brought up to market rent within the next 18 months, I aim to cash flow $1,666/mo with 10.9% CoC and a 7.86% cap rate (calculated from the beginning purchase numbers) .

From calculations and other research, it looks like I’d make about 15%.

To us, it feels that the builder or whoever calculated the sq footage back in the day, calculated the patio too.

Below are the rental calculations I've come up with.

As a nurse investor, I can weigh in on some of the business details: I am from CA so some of the info maybe different however you need to calculate in the cost of a licensed facility administrator, and staff either licensed or unlicensed per staff to resident ratios.

The lender will then use 75% of the projected rent to offset most or all of the monthly payment that would be added to your DTI calculations.

Now calculate rental income - expenses and divide by Total Cash Invested(avg down payment) ie.

Owner can draw the capital from the investment without it being a taxable event.

One thing they consider when insurance companies calculate the cost to rebuild is also everything that will go into the preparation before hand, ie; demolition costs, soil decontamination, permits, planning etc.