Improving the energy efficiency of the residential building stock has increasingly been promoted by policy makers as a means of reducing energy demand in the residential sector. We review the literature on some non-energy impacts of energy efficiency retrofitting measures aimed at increasing the air tightness and thermal insulation of residential properties. Specifically, we review the impact of retrofitting measures on indoor pollutants, mould growth, attenuation of radio signal and overheating.

Over half of the population of the world live in
urban areas. This means that efforts to meet human
development goals and sustain economic growth
must be concentrated in cities. However, the pursuit
of more prosperous, inclusive and sustainable urban
development is complicated by climate change, which
multiplies existing environmental risks, undermines the
effectiveness of existing infrastructure, and creates new
resource constraints.
In this paper, we conclusively demonstrate that there

This study presents three cost-optimal calculations. The overall aim is to provide a deeper analysis and to provide additional guidance on how to properly implement the cost-optimality methodology in Member States. Without proper guidance and lessons from exemplary case studies using realistic input data (reflecting the likely future development), there is a risk that the cost-optimal methodology may be implemented at suboptimal levels.