Hi @Eric Wiinanen
With purchasing the next house, will an underwriter use the potential rent income as Income? Given that you're not meeting the DTI ratio, a non-bank lender that looks at the property's cash-flow (based on the market rent) is the way to go. The difference between this type of lender/loan product and a bank will be in process, underwriting requirements, rates, and fees -- so basically everything except that you'll be able to get a 30 year fixed. So to answer your question, yes, this lender will use the potential rental income. They will figure out what the DSCR (debt service coverage ratio) is on the property. That's achieved by taking the Gross Monthly Rent divided by the monthly loan payment of principal, interest, taxes, and insurance (as well as any dues). The gross monthly rent is provided to the lender by the appraiser. They will do a market rent analysis to determine what the monthly rent for the property you're buying is.
What is the process to do that since there wouldn't be any current lease, past rent history, etc.? How would you approach this? I answered that above. But, again, if there's no lease that should not be a problem. When the lender orders the appraisal, they'll request an additional form from the appraiser, which is the market rent analysis. The appraiser will get comps for both the value of the home (sales comps) and the market rent (rental comps). When you start looking at properties, you'll have an idea of what you expect it to rent for (based on other similar listings in the area). You'll get that to the lender you're looking to get a quote from.
You can reach out to any non-bank lender (DSCR lender, property cash-flow lender) and informally run through a scenario. They'll be able to provide you with a quote pretty quickly.