The length of the ground loop depends on the size of your home and the amount of heat you need - the longer the loop the more heat can be drawn from the ground. Usually the loop is laid flat or coiled to a depth of about two metres, but in cases where there isn’t room to do this in the garden its possible to use a vertical loop to a much deeper level of up to 100 metres. The cost of installing a typical system starts from about £7,000.