I was simply reacting to your assumption that a Council would actually oversee building work..!Please explain,I don't understand your comment?
The way this has been done for many years is that the whole thing is supposed to be covered by contract and certification. It is simply a box ticking exercise! The level of sub contracting that goes on the building trade means that in practice, nobody knows what is happening, and nobody cares as long as the paperwork looks ok at the end..! (and the money is paid!)
Council staff these days are mostly office administrators who would not know a compression joint from a rag bolt. Construction firms are also mostly administrators and finance people whose actual knowledge of building is minimal. All expertise is hired in at the least possible cost for the shortest possible time...
The speed of modern construction means that you would have to have an inspector standing with each team all the time.. not going to happen!