Energy-retrofitting might be good for the environment, but what about the indoor environment?

In contemporary Danish renovation practice the energy consumption of houses is a major focus. However, it has been shown that a significant energy reduction entails new challenges regarding thermal comfort. This paper investigates how future renovations can improve thermal comfort by taking into account the specific house type and the architectural qualities.
The paper takes its point of departure in the development that has taken place within habitation over the past century. Our way of living has changed significantly during this period, and so has our indoor climate. Danes spend 80-90% of their time indoors and more than half of that time is spent at home. Therefore, the indoor environment in our homes is of great importance to our health and well-being.
While energy retrofitting can alleviate some problems with the indoor climate, it has simultaneously introduced new problems with indoor climate and comfort. Research has shown a shift in challenges regarding thermal comfort in Danish houses over the past decades. A survey shows that houses built before 2000 typically have problems with draught and cold, whereas houses built after 2000 tend to have the opposite problem – overheating. This problem is also current in energy-retrofitted houses, where it usually occurs due to a highly sealed, insulated façade – a renovation procedure that often requires installation of a mechanical ventilation system.
So-called passive solutions can minimize the need for technical solutions and typically control heating and cooling, and so they have an impact on energy use as well as indoor climate and thermal comfort. However, only limited research has focused on the potentials of using passive solutions in regard to indoor climate. Therefore, this paper seeks to unfold the potentials of passive indoor climate solutions and thus contribute to a sustainable renovation practice based on the original architectural qualities of the house.