The house has a walk-out basement with 1 bed 1 bath and a full living area.We furnished the basement and rented it through Airbnb - the income fully covered our mortgage and utilities!

As long as 75% of the rental income minus the PITI on the investment property is a positive number, I believe that would add money to my reported income without worsening my debt (since the rental PITI isn't double-counted).

Purchase price: $365,000 Cash invested: $93,000 4 unit, 13 beds/4 baths (5, 4, 2, 2) What made you interested in investing in this type of deal?

I only had money to buy a 1-bed condo at the time, and I had some mental issues to sort through and the SFH within my budget at the time were in areas that was far away from the hopsital I was attending regularly so in short, I bought the condo. 

The property is a 1 bed 1 bath 700 sq ft home with a kitchen and living area.

Don't go overboard, but you can double your living space. 

I have seen some higher end house hacks work too (sold one last year where the clients were still out of pocket about $1400 a month (getting $2200 rent) on an 8 bed 4 bath two unit which duplexed down in unit 1 and up in unit 2.

Then we have to double the rent, deposit and run more conservative numbers causing the cost of housing to double over the next say 10-15 years.  

It was more than double what it should be.

Double check with your lender to confirm.