inside Number 9

I'm sure it's down here somewhere ...   See extra for a second opinion.

Our houses were built 6 or 7 years ago.  There are 9 in total and they were assigned plot numbers, 1 to 9. Plot 1 was the first to be built and ours - plot 9 - was the last. Seems logical enough. And then we were assigned postal addresses.  
On a cul-de-sac like ours, it appears Royal Mail prefer house numbers to run clockwise - the plot numbers run anti-clockwise. So plot 1 eventually became house no 9 and we (plot 9) became house no 1. With me so far?

Not every one is. The utility companies still work on the original plot numbers.   Every so often we get someone in orange overalls knocking at the door asking which house/plot number we are.  Today it's the water company.  We have a new water meter.