Government regulations do not allow for connection directly into a standard 240V plug in a house or garage with a 3 pin plug. There is the possibility of overheating and fire at the plug if demand for power is high from the camper, such as the use of toasters, kettles etc. all at the same time. If a fire occurs as a result of plugging directly into a house, you will be liable for any damage. Campgrounds use a 3 phase source of power supply, your vehicle is equipped with this and you can plug directly in to mains power at any campsite.