Its a measure of good vs bad investment.However, in the case of the author where he lives in 1 of the units, I'm not sure sure you should consider counting the 12K income.  

@Javar Hargrave what I’ve been taught is to take a tape measure and pen and paper with you when you go look at a house.

It seems like more and more areas that are high traffic (vacation destinations) are putting measures in place to discourage or stop short term rentals (Airbnb type or <30 day rentals). 

Example:Heat is measured in BTU'sElectric baseboard or space heaters $35.13 / per 1,000,000 BTU'sNatural Gas                   $10.02 / per 1,000,000 BTU'sHeat Pump                    $14 / per 1,000,000 BTU'sIt is 3.5 times as much multiplied by every month you are paying to heat the property.Here is a free calculator offered on the Department of Energy's website:http://www.eia.gov/tools/faqs/heatcalc.xlsI just wanted to make you aware of your options and any necessary information before taking on that monthly expense.Also, with a central system, you control it (WiFi Stat).

Granted, this component can be mitigated to a point by bringing in an experienced partner or by using a reputable PM, but the point is a bank can, and will, see the big picture.You NEED to have your own funds into the deal for this to have a measurable chance of success.

The more complex aspects include circumnavigating the security measures intended to prevent scraping from occurring. 

You can use an IRR calculation or other measure that takes into account the cash flows to see how profitable the deal was.In conclusion:You can not win as you would have to imply there is only one way to make money with RE.

I haven't measured the deck size, but looking at pictures of similar sized decks this one seems like it's around 12x20 or 12x24 at the most.

Domestic air travel in China is back to pre-pandemic levels and in Singapore there were all of 5 positive cases of Covid as the country has been diligent on preventive measures and contact tracing.

My recommendation: Identify the standard unit of measurement you are using to evaluate your markets.