I've included an example below to help illustrate this.So different lenders have different rates (which do vary even for DSCR loans) but these are factors they all consider.See example below:DSCR < 1Principal + Interest = $1,700Taxes = $350, Insurance = $100, Association Dues = $50Total PITIA = $2200Rent = $2000DSCR = Rent/PITIA = 2000/2200 = 0.91Since the DSCR is 0.91, we know the expenses are greater than the income of the property.DSCR >1Principal + Interest = $1,500Taxes = $250, Insurance = $100, Association Dues = $25Total PITIA = $1875 Rent = $2300DSCR = Rent/PITIA = 2300/1875 = 1.23If a purchase, you also generally need reserves / savings to show you have 3-6 month payments of PITIA (principal / interest (mortgage payment), property taxes and insurance and HOA (if applicable).

@Wells H. you can spend DAYS driving through Detroit!

Investing is different from speculating, in that it’s data driven and therefor predictable and you have factors that play in that covers your downside and strengthen your chance of upside. 

Entrepreneurial drive.

You can close in an LLC and don't need to provide employment history, income or tax returns, and DTI isn't a factor.

When you drive out to your example I'd be thinking.....hmmmm why is there a tennis court next to the deal I'm getting ready to buy? 

One of the biggest factors at play right now is data transparency among lenders, we can see a lot of the industry-wide trends.

Nonetheless, I am not out to impugn anyone's intentions and I do understand (as Jay rightfully points out) that the self-employed (my situation for the past 20 years) especially run into times in their lives when conventional lending sources are of no use due to limited reportable income and other factors (such as when, for example, you retire in your 50's and begin to live off of your lines of credit, etc.). 

Location and amenities are the two most important factors that bring potential renters to an STR. 

Most (not all) HELOCs require that the property is titled to an individual (not LLC) and are full doc, meaning your employment history, income, DTI etc will be factors.