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.

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.).

Cooperation between public and private sector has achieved a remarkable widespread, in the Italian context, over the last two decades. Nevertheless, the increasing difficulty in accessing the capital market and the rising cost of funding sources, both noticeable over the past few years, led to a slowdown of Public–Private Partnership (PPP) initiatives. Meanwhile, the community is expressing new needs to be satisfied, such as the conversion of brownfields, the recovery of housing stock dating back to former times, as well as the refurbishment of public offices or schools.