The amount of kWh of heat a house needs in the UK can vary depending on a number of factors, including the size of the house, the level of insulation, the number of occupants, and the climate. On average, a UK household uses around 20,000 kWh of energy per year for heating and hot water or 55kwh per day. However, this can range from around 8,000 kWh for a small, well-insulated house with a single occupant, to over 30,000 kWh for a large, poorly insulated house with multiple occupants.