Lender Rules Re Mortgage-to-Income Ratio For Investors?

[Mike C.]

If lender's maximum desired ratio for borrower's mortgage payments to gross monthly income is 28%, how can a person with average income ever have a mortgage on more than one "average" property?

Income from investment property rents would need to be at least 3.6 times the mortgage payment for the 28% rule to allow an ongoing buy-rent-buy-rent business model, which of course isn't realistic.

It seems lenders must change the formula for people who buy properties to rent. Are there common lender guidelines, similar to the 28% rule, that can be useful when considering various investment scenarios?

We have one house that's been rented for a few years and are now looking at another that seems attractive. Making a feasibility study sheet has been very educational as so many questions are raised .

Any advice will be appreciated.