It is far less Rocket science and far more a trained eye to understand what little tasks will take a lot of time.The other easy way around this is to find a reliable GC and pay him for estimates.  

I am overwhelmed with the amount of amazing support and information that can be found here.Note investing is fascinating and I have been reading every book that I can find about the subject. 

So if anyone know how this can be accomplished (or have actually pulled it off) I would be fascinated to hear how!

@Chris Mason Fascinated with your (mortgage banking) perspective.

Searching and examining title is as much an art as a science and should only be done by those experienced in it and willing and able to absorb the loss if a mistake is made. 

Easy answer here is if you don't know what you're doing with venting, let a qualified HVAC company come in and get everything adjusted for you based on science rather than guessing. 

We were assuming we’d have to go the commercial route but this DSCR method does sound fascinating!

I have been fascinated with the "Tiny Homes" concept for while now and have seen many little tiny home villages pop up in different areas of the country.

This part of the business is more art than science.  

It's not rocket science to figure costs out.