One thing that springs to mind here. When I was an Apprentice Electrician, I was asked to measure the run from the pole, down a long driveway, under a cattle-stop and across the driveway. This was "on the way past" on the way to another job. All well and good, I aced that one, or so I thought. I'd left out the length that ran up the pole. It was 18ft too short and with a cut-to-length service from the suppliers 100km away....... Boy did I get a roasting about that.