Analysis of indoor air quality & thermal comfort parameters in building regulations in 8 member states

It is estimated that people spend 60-90% of their life in indoor environments. Therefore, it is obvious that indoor air quality (IAQ) and thermal comfort are of highly importance for the health and wellbeing of the population. Consequently, buildings should be designed to ensure proper indoor conditions. Furthermore, the need to mitigate climate change and to reduce energy import dependency, provides additional challenges for the design and operation of buildings and requires a dramatic reduction in their energy consumption and emissions. Based on that, the Energy Performance of Buildings Directive (EPBD, 2010/31/EU) asks EU Member States (MS) to significantly improve their regulatory and policy framework to ensure that minimum energy performance requirements will be met. At the same time, the EPBD, acknowledging the important role of IAQ, clearly states that minimum energy performance requirements “shall take account of general indoor climate conditions, in order to avoid possible negative effects such as inadequate ventilation”.
Projects and voluntary standards for very low energy buildings already prove that buildings can be energy efficient and at the same time contribute to outstanding IAQ and thermal comfort. But how do today’s building codes address these topics?
The overall aim of the paper is to provide an overview of the regulatory framework for IAQ and thermal comfort and to highlight the importance of having appropriate requirements for the parameters linked with these topics. The parameters that are studied in this paper are: ventilation rates, airtightness, indoor air pollutants, mechanical and natural ventilation, indoor temperatures, humidity and air velocity. The assessment focuses on the respective building codes for new and existing residential buildings in selected MS: Belgium (Brussels Region), Denmark, France, Germany, Italy, Poland, Sweden and the UK (England and Wales).
The results of the analysis show that all studied MS have at least a basic reference to IAQ included in their building codes. Minimum ventilation rates are required or recommended in all 8 MS and precise airtightness requirements are in place in 6 MS (BE, DK, FR, SE, PL, UK). Concerning thermal comfort indicators, indoor temperature requirements or recommendations range between 16°C (PL) and 28°C (FR) and recommendations with regard to humidity are given in 6 MS (DE, PL, IT, SE, UK).
For existing buildings, indoor air quality related requirements (ventilation rates, airtightness, etc.), can hardly be found in the analysed building codes. Regarding thermal comfort, even though it is often considered as a main driver for the decision of an owner/occupier to invest in renovation, it is rarely captured by national and/or European legislations.
Based on the findings of the paper, it can be concluded that indoor health and comfort aspects should be considered to a greater extent in the European and national building codes than it is current practice.