There's many horror stories about the size and the quality of re-bar and about the type, quality and mix of mortor and concrete.
If anyone is thinking of building their own and has no experience of construction there's so many opportunities to get ripped-off and also have a house which is not safe.
Nearly all the materials used will have a minimum specification as 'fit for purpose'
Even the so-called tin roof. You can buy cheap with very short life cycle and you can buy more expensive thicker longer lasting low maintenance, but there is a cost and someone had better know how to verify what's being delivered and then to verify what's actually being installed.
Caveat emptor!
