The existing residential building stock accounts for a substantial portion of worldwide energy consumption and greenhouse emissions. Improvements to the thermal performance of existing buildings is a vital activity to mitigate climate change, and often has additional benefits in the form of improved comfort, health and well-being for occupants. Despite the extensive body of literature in this area, it remains a difficult task to assess the performance of retrofit packages in occupied residential buildings.

There are indications that energy-retrofitted buildings can create risks for indoor environmental quality (IEQ) and therefore for health and comfort of occupants. A review was conducted to identify and verify those risks, within three themes: building envelope, heating, ventilating and air conditioning (HVAC)-systems, and occupants. Publications from the last five years in major peer-reviewed journals from different fields (energy, buildings, indoor air, social sciences) were found by using a variety of keywords (health effects, occupant behaviours, energy-efficient retrofitting, etc.).

In 2009, the European Union adopted high-level goals for renewable energy, energy efficiency, and greenhouse gas reductions with targets set toward the year 2020. This was followed in 2012 by adoption of the Energy Efficiency Directive (EED) (2012/27/EU), which included as a major component a requirement for Member States to create Energy Efficiency Obligations Schemes (EEOSs) on energy companies or equivalent alternative measures, and those provisions have now been in effect for three years.