This paper reviews empirical data from evaluations of the influence of residential energy efficiency retrofits on indoor environmental quality conditions and self-reported thermal comfort and health. Data were extracted from 36 studies described in 44 papers plus two reports. Nearly all reviewed studies were performed in Europe or United States. Most studies evaluated retrofits of homes with low-income occupants. Indoor radon and formaldehyde concentrations tended to increase after retrofits that did not add whole-house mechanical ventilation.

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.