Since airbnbs tax returns ard technically independent contractors, I have been told by several lenders that it takes 2 years of consistent Airbnb returns to be able to count it as income. The same is true of starting any other independent contracting business and claiming it as income. A traditional lease that is signed shows at least a one year "guaranteed" return. Lenders are more comfortable with the traditional buy and hold model. There are some things you can do:
1. rent out rooms of your primary residence to start building up the two years income needed
2. Get a one year signed lease for the property for the purposes of getting refinanced and then you can convert it to an Airbnb afterwards
3. Or, Find a tenant that would be interested in hosting the other room/rooms as airbnbs. (I have not done this approach but zeona McIntyre who has been on the podcast and blogs about Airbnb is a good resource)
I have thought about this a lot as I am having to get creative with my own debt to income ratio. My hope is that as STR become more mainstream, lenders will see the benefits