Today, buildings still account for almost half of the global energy consumption and carbon emission. This highlights the necessity to increase energy efficiency requirements worldwide in a common effort to reduce the construction sector's impacts on the environment. The current energy policies are driving toward a design that relies on airtight and highly insulated envelopes. As a consequence, energy efficient houses are found to have insufficient indoor air change rates, impacting on the indoor air quality and resulting in higher latent loads.

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.

Improving energy efficiency has long been advocated as a way to increase the productivity and sustainability of society, primarily through the delivery of energy savings. The impact of energy efficiency measures can go far beyond energy savings, and energy efficiency improvements can be an important contributor to economic growth and social development.

The untapped / hidden benefits of environmental policies are huge, this piece of research showcases and places a monetary value on the added benefits to our health, society and the economy that environmental investments and policy linked to energy efficiency can bring. Findings show that green policies can improve both our health and the economy and can go hand-in-hand. This study provides guidance to policy and decision-makers in developing a methodology for the inclusion of multiple benefits in a cost/benefit assessment of energy efficiency policy.

Heat pumps are relatively simple appliances. They share similar components to refrigerators and air conditioners and effectively move an external source of heat to where it is needed, such as in buildings for heating or the production of hot water. Their key value is efficiency; for each unit of electricity consumed to operate them, they produce multiple units of usable heat. Because of this, they require much less energy input for a similar heating outcome compared to combustion technologies, making them naturally cleaner and generally cost effective to run.