A common service trench with gas (yellow) and water (blue) pipes positioned at a depth to avoid damage from freezing and heavy loads.

Drainage pipework is surrounded by granular fill and is provided with flexible joints to facilitate movement in the ground gullys to accept waste outlets are set to the correct level before being bed in concrete. The depth of the pipework is variable as a result of the required gradient.

          

Electrical and gas installations enter the dwelling via externally accessible meter boxes. In this case they are set into the wall, but thay may also be surface mounted. These allow access by the service provider in emergencies or for meter reading.