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.

This report sets out the positive and negative impacts of improvements in energy efficiency in buildings that could come about through a recast of the Energy Performance Buildings Directive (EPBD). Successive studies have shown that energy efficiency offers many of the most cost-effective options for meeting global emission targets. In many cases, energy efficiency measures have been shown to be ‘negative cost’, meaning that it would be economically advantageous to implement them.

Global warming and environment problems caused by the excessive emission of greenhouse gases (GHGs), along with rapid economic development has attracted the attention of many countries and regions of the world. Reducing GHG emissions is essential to mitigate the threat of global warming. Household carbon (dioxide) emissions have been recognized as one of the most important contributors to climate change, with a significant impact on both the local and global environment, and various policy instruments have been implemented by governments to bring about the reduction.