@Scott Kunz I found it to be a waste of time.

There is such a thing as thick-walled copper piping, Type L.

I just don’t want to join because people just want money because I don’t have the money to waste, just trying to get started.

I was going to start looking around a bit but do not want to waste time if there is nothing like this out there.

It's far too easy for me to stray from the plan and end up wasting a ton of time chasing leads.

The effort included a retaining wall design, grading plan, water/ sewer, underground utilities, pollution controls, drainage, quantity of materials and construction specifications.

They are normally used to make retaining walls, But we made into a sitting area with fire pit (tractor rim). 

FWIW  any pushing out the outside walls of a flip project today the costs have exploaded!!!!   

I have a contractor set to come in a week to frame in some walls for our bedroom. other than that.

Yes, but you need to narrow it down a lot to have a coherent answer.You will have to look at (I'd recommend in this order) the city codes (if it's inside a city, many cities above 50-100k population aren't friendly to development of these), the county codes (most counties are friendly to these, but you will probably have significant issues in major counties like Bexar, Travis, Dallas, Denton, Tarrant, Harris, etc), then you will have to comply with the state-level (TCEQ and others) on the water supply and waste water treatment systems.To put it in perspective again, in say Dallas or Austin, you will likely have prohibitions or very significant hurdles on developing RV or tiny home properties even on unincorporated, "unrestricted," AG-zoned properties at both the city/municipal level and county level.