The ideal temperature for a house generally ranges between 18 to 22 degrees Celsius (64 to 72 degrees Fahrenheit) for comfort, health, and energy efficiency. The Energy Saving Trust and the World Health Organization (WHO) suggest heating your home to 18 degrees Celsius as a minimum to protect health, especially for healthy and well-dressed adults, while 20 degrees Celsius is recommended for vulnerable groups such as the elderly, young children, and those who are unwell. For individual rooms, warmer temperatures are advised in living rooms and bathrooms (around 19-24°C), while bedrooms are ideally cooler (16-19°C) to support better sleep. To save energy, temperatures can be lowered by 7-10 degrees when away or asleep, with a safe lower limit around 15-16°C to avoid risks such as respiratory issues and frozen pipes in winter. Generally, indoor temperatures above 25-27°C can become uncomfortable and pose health risks in hot weather. These temperature recommendations balance comfort, health, and energy conservation effectively.