The indoor temperature of a house affects both comfort and health. The World Health Organisation and UK health guidance provide recommendations that balance thermal comfort with heating costs and the specific needs of different occupants.

Recommended Living Space Temperatures

For most healthy adults, a living room temperature of 18 to 21 degrees Celsius provides comfortable conditions during the heating season. Many people prefer the upper end of this range, particularly when sitting still for extended periods, while those who are more active or younger may be comfortable at the lower end. The optimal temperature for an individual depends on factors including age, health, activity level, clothing, and personal preference.

Bedrooms

Sleep is generally better at cooler temperatures than waking. The recommended bedroom temperature for good sleep quality is 16 to 18 degrees Celsius. A room that is too warm disrupts sleep onset and sleep quality for most people. Babies and young children require warmer sleeping environments, typically 16 to 20 degrees Celsius, and should never sleep in rooms that become very cold.

Minimum Safe Temperatures

The World Health Organisation recommends a minimum indoor temperature of 18 degrees Celsius as the lower threshold for avoiding adverse health effects for sedentary adults and for rooms used by vulnerable groups. For the elderly, infants, and people with health conditions, maintaining at least 18 degrees Celsius throughout the home during cold weather is important for health. Below 16 degrees Celsius, significant respiratory health risks begin to emerge with prolonged exposure.

Fuel Poverty and Cold Homes

Households in fuel poverty may struggle to maintain adequate heating temperatures due to the cost of energy. The government's definition of fuel poverty considers a household fuel poor if it would need to spend more than 10 percent of its income on fuel to maintain a satisfactory heating regime. Cold homes are associated with significant health costs including excess winter deaths, respiratory and cardiovascular illness, and mental health impacts.

Summary

The recommended living space temperature is 18 to 21 degrees Celsius. Bedrooms are recommended at 16 to 18 degrees for good sleep. The minimum safe temperature is 18 degrees throughout the home for vulnerable groups. Below 16 degrees, health risks increase significantly. A programmable thermostat maintains consistent temperatures efficiently and avoids excessive cold during unoccupied periods.