Heat, energy efficiency, smart technology and health evidence review

Family warming their feet in front of home radiator, photo by Evgen/Adobe Stock

Researchers found clear evidence concerning the negative health impacts of poor indoor temperature and ventilation. The study also identified that improved heating technologies and measures to increase the energy efficiency of buildings are effective in improving several key aspects of the indoor environment, though evidence on positive health impacts were mixed.


According to recent Eurostat data, almost 4 million UK residents are unable to keep their homes adequately warm. People living in homes that are too cold can have a significant impact on public health, an issue associated with around 34,000 additional winter deaths per year.

Recent improvements in energy efficiency and heating technologies have been widely discussed in light of their benefits for the environment, reduced heating costs and energy security, however they also have the potential to improve public health.


RAND Europe was commissioned by the Department for Business, Energy and Industrial Strategy (BEIS) to conduct a rapid evidence assessment into the health and wider impacts of poor indoor heating in the home and workplace. The study also explored whether introducing energy efficient, renewable and smart heating systems had an impact on health and the indoor environment.


The prevalence of poor indoor heating in the UK is fairly high

  • A key underlying reason for poor indoor heating is fuel poverty, which refers to a household being at risk of falling below the poverty line if they met their full required fuel costs. Members of households living in fuel poverty also tend to be generally more vulnerable to various health risks.
  • Excess indoor cold is linked with a higher risk of mortality and other health issues, particularly for certain groups such as the elderly, infants and those with existing health conditions. Living in a cold home is also associated with a higher risk of poor mental health, increased blood pressure, and slower recovery from cardiovascular disease.

New heating technologies and increased energy efficiency of buildings are effective in improving several key aspects of the indoor environment

  • New heating systems and energy efficiency interventions were found to increase indoor temperature and perceived thermal comfort significantly. They also resulted in reduced humidity levels indoors, though evidence on their impact on levels of mould was mixed.

There is mixed evidence on the positive health impacts of new heating technologies and energy efficiency improvements

  • Despite there being mixed evidence around positive health impacts, one important factor to ensure better health outcomes appeared to be the proper functioning of the various technologies installed.
  • While energy efficiency improvements are associated with a reduced number of excess winter deaths, an association with a higher number of heat-related deaths in summer was also found. Such an issue is likely to become even more relevant in view of climate change.