A lot of it is contractual. GMPTE/TfGM/ZQRSXA ...whatever they are called this week as with any building contract they will not sign off a job site unless it's been checked, double checked, gauge tested with a tram, electrically tested, then ran with a trial service for a couple of months - annoyingly slow, but ultimately if a crud job is signed off, it's us taxpayers that end up paying to fix it.