Couple of questions - firstly the connection to the water meter is only 2ft deep does this mean I will have to run the trench lower than the meter. Secondly I have told the person doing the groundwork I need a 100mm duct through the wall to take the pipe, he says it doesn't need to be this size. Done many repairs to mains but this is the first full replacement I have undertaken.
Min 750mm - most water companies have details on web site, otherwise see Water Regs. Some want to see the trench before you backfill, and all want to charge you dosh for making the connection.
you will need a duct to allow a long radius bend and insulation over the mdpe were it rises up out of the ground inside the house, i did one and trenched it out at 1m and found the main in the pavement at 450mm, double standards :^O