Indoor climate has a great impact on human well-being, including comfort, productivity and health. If office buildings were designed and operated in a way that improves indoor climate, work life quality and productivity would increase significantly. Hence, money can be saved as worker salaries and benefits greatly exceed the costs of providing and operating buildings.

We spend 80-90 percent of our time indoors and about 16 hours every day in our dwelling. The impacts that we are exposed to in the indoor climate are consequently of great importance for our health and well-being (MST 2006). The quality of indoor air is affected by many factors, ranging from the surroundings and the construction of the building to its layout and interior decoration. In addition, chemical emissions from building materials like formaldehyde in plywood and flame-retardants can affect indoor air quality, which is why the ventilation system is a key aspect in regulating indoor environment. Lastly, consumer products, including furnishings, electrical appliances and the use of polishes for cleaning surfaces have an effect on the indoor environment (EEA 2013; MST 2006).

Indoor environment impact on working performance

Designers and operators of buildings normally only consider initial costs and expected energy and maintenance costs when making investment decisions. However, a study recently developed estimates of how ventilation rates and temperatures affect work performance and hence productivity (Fisk and Seppanen 2007). Similarly, another study has shown that poor indoor air quality in buildings can decrease productivity in addition to causing visitors to express dissatisfaction. The size of the effect on most aspects of office work performance appears to be as high as 6–9% (Wyon 2004). The financial benefits of improved indoor environmental quality may include the value of improved work performance, reduced absence, and reduced health care needs.

Large paybacks can be expected from many changes in building design, operation, and maintenance that improve worker performance because worker salaries and benefits greatly exceed the costs of providing and operating buildings. However, the economic value of these changes in work performance, absence, and health are normally neglected. To better inform decisions about investments in building design, retrofit, or operation, it is common to employ cost-benefit analyses that account for initial equipment costs, energy costs, maintenance costs, and taxes. Example cost-benefit analyses from Berkeley University indicate that benefits may often exceed costs by a factor of 10 or more (Fisk and Seppanen 2007).

Buildings often have a durability of over one hundred years, but parts of the buildings last a shorter period and have to be changed when the need arises. Inappropriate or insufficient operation and maintenance of the building can lead to accelerating building defects and unsatisfactory indoor climate conditions.

Sufficient moisture and insufficient ventilation are key conditions for microbial growth indoors. It is estimated that dampness affects 10–50 % of indoor environments in Europe (WHO 2009). Dampness not only facilitates the growth of many biological agents, but initiates chemical or biological degradation of materials, which also pollutes indoor air (EEA 2013; MST 2006).

Airing and ventilating provide the best protection against moisture, odors, chemical compounds, particles, allergens, microorganisms, in that airing dilutes the unfortunate components. However, the ventilation system requires special attention during design and operation, if it is to work properly. Lack of cleaning of filters and poor maintenance can cause annoyance and symptoms for the occupants of the building.

In addition, there is a conflict between energy efficiency and indoor climate goals because increased ventilation is associated with improved work performance and better health, yet at the same time often increases energy use. Given the concerns about global climate change resulting from the use of fossil fuels for energy, there is a strong need for technologies and practices that bring about the productivity benefits without increasing energy use, and ideally with simultaneous energy savings. It is usually more energy-efficient to eliminate sources of pollution than to increase outdoor air supply rates.

Regulation not in place

Currently, there are no statutory requirements that pertain directly to indoor air quality. No regulations have been developed in the EU to cater specifically for indoor air quality due to the complexity of the issue and the fact that there are many interacting factors that need to be considered. Thus, it is relevant to note that health-based indoor air quality guidelines for several pollutants, including benzene, carbon monoxide, nitrogen dioxide, polycyclic aromatic hydrocarbons and radon, have been issued by the WHO (2010). For public buildings, for example schools, there is legislation with respect to ventilation and CO2 build-up. Still, the risk management by the public authorities is difficult, because sufficient knowledge to make a proper risk assessment is only available for a few factors, i.e. radon, tobacco smoke and asbestos (WHO 2009; EEA 2013).

Due to the complexity of indoor pollution sources, health effects pathways, and the multitude of parties responsible for generating and controlling indoor air pollution, measures to improve indoor air quality need to be part of a comprehensive management strategy as well as new regulation on design and maintenance of office buildings should address indoor climate aspects.