I want to build an ADU in our backyard and rent it out.

HiMy name is Nathan Lieber, I am new to real estate investments in Memphis.I am interested in buy and hold or fix & flip deals of SFH up to $100K.I would be happy to get some tips and start building some connections and local team.Thank you for your helpNathan Lieber

My own opinion is by rationale of why the 15 year rule exists (to not discourage new building) it should not apply to either building.  

However, if the $4k/month also includes utilities and other maintenance (i.e. gardening, pool service, etc.) then you'll have to factor that in as well. 

They don’t build new hangers very often as there is limited airport land.

However, these buildings have no mortgages or liens and the areas have become quite desirable to young professionals since acquired.

This criteria is for 1-4 and 5-8 unit programs.I've included an example below to help illustrate this.So different lenders have different rates (which do vary even for DSCR loans) but these are factors they all consider.See example below:DSCR < 1Principal + Interest = $1,700Taxes = $350, Insurance = $100, Association Dues = $50Total PITIA = $2200Rent = $2000DSCR = Rent/PITIA = 2000/2200 = 0.91Since the DSCR is 0.91, we know the expenses are greater than the income of the property.DSCR >1Principal + Interest = $1,500Taxes = $250, Insurance = $100, Association Dues = $25Total PITIA = $1875 Rent = $2300DSCR = Rent/PITIA = 2300/1875 = 1.23DSCR lenders generally let you vest either individually or as an LLC.

I love the seller financing model because if the property is owned free and clear, there are no banks you need to deal with and for the sellers they will receive more than the negotiated purchase price once factoring in the interest payments and they can defer having to pay the capital gains.

For the past month, I've been doing a short term rental for my 1 bedroom apartment in a 3 unit building.

Build a relationship now for the future or switch to a better tax person.