Checking with the departments one by one for each land listing that looks promising seems very inefficient.Regarding costs, i hear build costs of containers vs stick built being similar, but I had wondered if that is taking all aspects into consideration like build time, foundation and site prep requirements, etc. yes, steel cutters and welders are a special trade but the structure can arrive pre-built and potentially just sit on concrete pier foundations if the soil and zoning allows.

I think it's because the basement (concrete, cinder block) walls are in direct contact with the soil (newer homes usually have a barrier or membrane fastened to the outside walls, which keeps water away from the wall, and forces it down to the footings, where the weeping or drainage tile is located), which contains a fair amount of water.  

We just recently built an ADU from the ground up ~1100 sqft in Rosemead that cost us about $250k when all was said in done, this one requires a longer drawn out process such as soil tests, etc since you will be building framework from the ground up.

Predevelopment costs include site preparation, architectural designs, permits, soil tests, impact fees, property survey, utility trenching, land clearing and energy reports.

The age of the house, the location/market, expansive soils, ground water levels, and many other things can affect the answer. 

My personal line in the sand is "just say no to unsecured debt", even with a personal guarantee and an immaculate FICO score. ( There are plenty of people on prosper & other peer to peer lending sites doing this everyday without flinching, I couldn't stomach it.)I have been on both sides as a lender & a borrower.As a lender, I would trade additional cross collateral instead of a personal guarantee any day.

@Kelton Johnson  and were you live.. there is Hail and wind damage and your deductible and foundations.. every deal I have funded in your town had or has major foundation issues.. its not if its when .. and of course none of the location turn key companies mention this pesky reality of owning properties were you have major expansive clay soils.

A topsoil screen , sell topsoil , if its sandy , screen sand , if its rocky , sell stone .

American soil. 

From my understanding it is not uncommon in Texas to have foundation repairs due to the rough, dry soil that can shift (would love perspective from any DFW investors).