Today's household machines began as very simple devices and were improved step by step. A brick box with a stove inside became central heating, a barrel with a big handle became the automatic washing machine, a charcoal-lined box became the refrigerator, and a stone trough became the toilet.
Most households did not jump to modern convenience all at once. They added comfort bit by bit, one appliance at a time, as each new technology became cheaper, more widespread, and more a normal part of everyday life.
Home systems like heating, lighting, plumbing, and washing machines start out as conveniences. Over time they become systems everyone depends on, so basic that most people can hardly imagine surviving without them.