@Heather Jensen Are you looking to build a house for investment or your primary residence? 

I did not have much luck with traditional banks even though my partner is a GC and has done multiple additions and garages.

The primary challenge was ensuring the property met all zoning requirements for residential use after being a commercial space.

The TransUnion "ResidentScore" is similar to a traditional credit score but is tailored specifically for rental screening.

Start with your primary residence if you are currently renting.You can buy a duplex with only 3.5% FHA Loan and rent out the other side while you continue to learn about real estate investing.

I wonder if I could reach out to any local brokers who would know of investors that perform these loans, since none of the traditional lenders do.  

Buy and occupy for 2-3 years, improve it, and sell it tax free (up to $500k if you and your partner both OO for 2 yrs) so you can move onto the next one.Starting to think team house hacking might be the primary way for folks to make this model work nowadays.

We have >$2m in debt spread across the investment properties and our primary residence.

But then wouldn’t I be losing all the gained equity in our primary home?

In Denver where I invest it's actually a PLUS to not have the other unit considered separate because permits are only allowed for STR if you're renting out your primary residence and I know many folks who put a locking door on part of their home and have a separate external entrance to that part of the house, and rent it out as an AirBNB without it being considered an additional unit by the city.