I think I'm more interested in the BRRR, my main goals are to develop environmentally friendly, energy-efficient, and affordable houses.

The most cost efficient is to find something already built: a large house where you can rent out bedrooms, a multi unit where you can live in one and rent the others, a house with extra square footage that allows you to add a private entry and create a little studio or 1 bd unit to LTR or STR (?)

Everything on the market is wildly overpriced and as we all known would most likely need some sort of substantial repairs to get it back up and running efficiently.

We are finally to a place where I feel we are running at 90% efficiency and constantly reviewing and training to get better.

They are pretty affordable (I think $70 when I got mine, or free if income qualifies) and you can learn a lot from them, plus they give free smaller energy efficiency upgrades and write out a plan detailing potential upgrades for you. 

I believe that in most cases, what I pay them, is recouped by getting things done correctly and more efficiently. 

A really good GC will explain to you the options -- from meeting the minimum to pass inspection to going beyond the minimum and delivering a better product (maybe you want better insulation, higher ceilings, upgraded features, more efficient energy use ... 

I think this is exactly what I need to be more productive and efficient. 

I hear you hate mortgages and there are many options to sort this out efficiently, work with a non-QM lender to get 30yr fixed.

I was thinking if i spent about 10k on new stainless steel high efficiency appliances we would see a decent return in equity.