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Why indoor environmental quality (IEQ) matters: towards healthier buildings

Webinar in the light of the extended programme of the European Sustainable Energy Week21st September 2022

‘Why Indoor environmental quality (IEQ) matters: towards healthier buildings’



On the 21st of September 2022, EVIA together with LightingEurope and eu.bac, organised a joined webinar to highlight the importance of Indoor Environmental Quality (IEQ) for the health and the well-being of Europeans. This event, held under the auspices of the extended programme of the European Sustainable Energy Week, featured several high-level experts from the research community, the European institutions, the health and energy sectors, and national organisations actively involved in the promotion of IEQ.


Although the COVID_19 pandemic has shed light on the topic of IEQ, its importance remains undermined and minimised compared to the interest given to energy efficiency and decarbonisation. Yet, these three topics are largely interdependent and deserve to be addressed together thanks to an holistic approach. Speakers demonstrate with scientific studies and surveys the consequences for human health and well-being of not addressing properly the IEQ. Available tools such as smartness in lighting, building and ventilation systems are being reviewed, as well as state-of-the-art tools to rate IEQ in buildings. The steps taken by the European Union in the matter is also addressed through the presentation of the main provisions of the Energy Performance of Buildings Directive (EPBD).


Andrea Voigt (Head of Global Public Affairs at Danfoss Climate Solutions) started the webinar by addressing the importance of Indoor Environmental Quality before introducing the panelists:

  • Mr Pau Garcia Audi, Policy Officer at DG ENER
  • Pawel Wargocki, Associate Professor at the Technical University of Denmark
  • Ourania Georgoutsakou, Secretary General of Lighting Europe
  • Pierre Cruveillé, Public Affairs director of the ALDES group
  • Driss Samri, Head of the Health and Comfort Operational Division at the French Scientific and Technical Centre for Buildings (CSTB)

Many of us are seating at home right now, or in their offices, meaning everybody is indoor. This simple fact already demonstrates the importance of IEQ in our daily lives. Yet, it is still a topic falling under the table. Indeed, people tend to talk more about energy efficiency and decarbonisation although IEQ is equally important. It is especially true when considering that our buildings are becoming tighter and tighter driven by environmental policies and energy efficiency requirements. It is also known that the consequences of bad air quality can be dramatic, as COVID-19 well proved.


Pau Garcia Audi (PG), Policy Officer at DG ENER – Buildings and Products

The importance of IEQ is reflected in a number of European legislations but the focus will be today on the EPBD. Its revision aims to reduce buildings’ greenhouse gases (GHG) emissions and final energy consumption by 2030 and to provide a long-term vision for buildings to contribute in achieving climate neutrality by 2050. The revision is also embedded in the framework of the Renovation Wave, taking into account not only the energy efficiency of the renovation, but also the sustainability and the health and well-being and the occupants.

The Nearly zero energy to zero emission buildings provision requires the introduction of a monitoring and controlling of the air quality. Member States are up to define air quality and to ensure the necessary equipment are installed in the new buildings to control the latter.

Among the main provisions on existing buildings, many of them aim to trigger renovations. The requirement to have indoor quality monitoring controlling is, for instance, also valid in case of major renovations. The minimum energy performance standards (MEPS) provision represents an obligation to renovate the worst-performing building stocks. The National Building Renovation Plans ensure that Member States develop plans to decarbonise their existing building stock by 2050. The European Commission also introduced a new definition of deep renovation as a renovation that takes the building all the way up to zero emission building.

Provisions have also been implemented on information tools. Elements from the Energy Performance Certificate have been modified to improve their quality and their comparability. As an example, common templates were created to report the presence of indirect monitoring and control mechanisms in the building.

Another crucial provision is the one related to inspections, now extended to standalone ventilation system. This provision comes in response to studies indicating that ventilation systems tend to degrade their performance overtime, and therefore fail at maintaining the necessary indoor quality levels. These types of inspection would help to ensure that the ventilation systems perform effectively over the lifetime of the building. The Smart Readiness Indicator (SRI) is now also required for large non-residential building as of 2020. It measures the smartness of the building which enables to have a clear vision of how the building maintain the energy efficiency and the indoor quality. The provisions of the renovation passports, the SRI and the inspections are creating information on the ventilation systems which are then stored in databases. These databases largely facilitate access to information which is believed to be one of the drivers for the building sector renovation.

AV: Do you think the problem of indoor quality is understood by everybody in the same way? Is the importance of IEQ really fully grasped? And do you think that tackling this aspect will really happen in the way the Commission has envisioned?  How confident are you?

PG: After the COVID pandemic, the problem of bad indoor air quality has been much more visible than it was before. Everybody is now aware of the importance of the issue but how much of the relevant provisions is everybody willing to accept will be observable at the beginning of 2023.


Pawel Wargocki (PW), Associate Professor at the Technical University of Denmark

To provide some context on the issue of IEQ, it is necessary to go back to our evolution as human beings, when we switched from being outer species to indoor species. Our habitat changed from the environment to buildings where we spend today on average 85% of our time, as surveys performed over the lifetime of a person show. Most of the time we spend in buildings is in residential environments, mostly when we sleep but also when we work and we do leisure activities.

The IEQ determines our quality of life in buildings through four parameters. Besides indoor air quality, three other components need to be consider: the thermal environment, the acoustic environment and the lighting. Those parameters are measurable through different tools. For thermal environments, we are looking at the objective parameters that are the temperature speed and the relative humidity. For the acoustic environments, we check at the noise level, the acoustic pressure and the reverberation time. For lighting, we check the illuminance, the daylight factor and the glare. Finally, for the indoor air quality, we have a look at the CO2, the ventilation, the particles, the organic pollutants (TVOC) and the inorganic pollutants (NOx, ozone).

It is really important to check these parameters because there are significant consequences if we neglect them. First of all, it reduces our comfort and well-being which can have an effect on our psychological and physiological conditions. Poor IEQ may also result in an increased prevalence of acute non-clinical health symptoms. Moreover, it is estimated to reduce work performance from 5 to 15%. Poor IEQ also disturbs sleep quality.

AV: If you were to give a priority on what needs to be done regarding IEQ, what would you choose?

PW: The priority is not to delay monitoring of the buildings. We witness in other discipline that a proper monitoring information results in improvement and advancement of technologies and conditions. We know that the decarbonisation efforts may compromise the IEQ levels, so if we don’t check the compliance of the buildings with adequate air quality, consequences that were mentioned earlier will follow.

AV: What exactly do you mean by monitoring?

PW: Monitoring is the measurements of the parameters that define EIQ (acoustic, air quality, thermal, light). It enables to learn more about the performance of the building.


Ourania Georgoutsakou (OG), Secretary General of Lighting Europe

Smartness is an essential ingredient to delivering indoor environmental quality. If IEQ is properly used, it will have positive impact on the health and well-being of the occupants. We spend about 90% of our time indoors, so building are effectively about people. These are the biggest value of buildings. Now is the time to kick start the changes because the technologies and the products are available, and we are on the verge of deep renovation waves, so the choices we are making today will remain for a decade and more. What is important is that Smart readiness considers health factors as important as other factors to fully reflect the importance of IEQ.

Lighting is a good illustration because it can deliver immediate and very significant reduction in the cost and the use of energy. Optimised lighting systems can enable us to achieve between 20 and 29 TWh/year savings until 2030, according to a European Commission’s study.

Lighting also impact our well-being. In 2017, the Nobel prize for medicine was awarded to a group of scientist who studied the circadian rhythm of humans. They showed that our body clock is adapted to cycle of light and darkness which regulates our behaviour, hormones levels, body temperature and sleep patterns. This means that our well-being is also affected when there is a mismatch between the external environment and our internal clock. The light does not only impact our vision but also our body in terms of alertness, cognitive performance, sleep/wake cycle and mood. Our bodies are made to live under dynamic light, meaning the right light must be delivered at the right time and at the right place. For instance, a warm light is needed when waking up whereas a bright white light is needed at work when we need to concentrate. Offices in Madrid (Spain) and Malmö (Sweden) have already developed a dynamic lighting system that helps synchronizing the circadian rhythm of the people to the daylight cycle.

Smartness can adapt the color temperature, the intensity and the where/when of the light. Other building systems can also do that. For example, smart ventilation would not only improve energy efficiency but also indoor air quality because it allows the air flow to adapt depending on the concentration levels of the pollutants in the air therefore enabling air renewal to be tailored to the needs. Other building automation and controls can make buildings healthy and comfortable by monitoring parameters such as CO2 levels, humidity and light levels. They make sure that the different systems don’t work against each other and are optimizing energy use.

The technology, the science, the knowledge, the products are there. Now is the time to install it in our buildings and deliver buildings that are good for people and the environment.

AV: Are there any studies or reports that quantify these findings?

OG: As new installations come out, people measure how people feel but measuring a mood is quite hard. A study dated of 2014 showed that the employees performed about 12% better due to the changing of lighting. Students performed 14% higher scores in their exams because their different cycles of concentration and relaxation were adapted to the lighting. Another study in a factory demonstrated an improved performance of 18%.

AV: Many Member States decided to turn off the lights in the streets or to stop illuminating buildings, may it have any impact on the environment quality ?

OG: We need to consider the consequences of turning the lights off. One of them is that the people may feel less safe walking in streets and buildings. With smartness, we can do both because sensors can switch on and off the lights only when is needed, therefore providing safety and comfort for the people, but also energy savings. In lighting, we are at that curve of renovation cycle. Recently, the Commission decided to ban old lighting technology like fluorescent tubes and mercury containing lamps. So now is really the time to renovate lights and to make the right choice to provide energy savings and comfort and safety.


Pierre Cruveillé (PC),  Public Affairs director of the ALDES group

We are now well documented about the importance of ensuring a good air quality in buildings. The COVID crisis definitely shed even more light on this requirement. Indeed, bad indoor air quality is a major public issue. The World Health Organization (WHO) estimates that about 120 000 Europeans die prematurely each year because of poor indoor air quality which causes cancer, cardiovascular diseases. These have far reaching economic consequences: the WHO estimates that the annual financial impact for Europe is about 260 billion euros.

Mechanical ventilation enables to remove pollutants from the indoor environments and prevent through filtration outdoor pollutants to enter the indoor environment. In 2017, the Joint Research Center  (JRC) of the European Commission promoted healthy and highly energy performing buildings in the EU. It supported the implementation of related requirements of the energy performance of buildings directive. On page 132 of their report, the JRC indicates that mechanical ventilation, if properly operated and maintained, enables to increase the removal of pollutants and dust leading to an overall improvement of air quality and reduction of health-related problems. This shows that ventilation has an essential role in making buildings’ occupants healthy by contributing to establish an appropriate indoor air quality level.

Mechanical ventilation has therefore an essential role to play to ensure good indoor air quality in buildings. Yet, when we look at the current situation of the building stocks in Europe, we see that there is room for improvement. Around 89% of European dwellings are, either not equipped with a ventilation system, or use a system that does not guarantee a sufficient air renewal all the time. Very often, the occupants do not get the benefits they should enjoy because the systems are outdated or are not performing as they should due to a lack of maintenance.

EVIA, as part of an informal gathering bringing different associations, is calling for dedicated legislative and regulatory measures to make sure that buildings’ occupants benefit of efficient ventilation technology solutions. First of all, the status of the ventilation system should be assessed systematically in each renovation project to ensure minimum air flows are always available. This aspect is often overlooked. In France, for instance, only 2/10 of building renovations actually take on board ventilation systems. Secondly, once such device implemented, it should be checked by an independent third-party to make sure that it has been well installed and that the air renewal rate complies with expectations. We need regularly inspections to keep up with the initial performance. Once we identify non-conformity or problems, necessary actions need to be taken. It is a measure that should be extended to all technical building systems contributing to IEQ parameters. Thirdly, we need mandatory indoor air quality requirements based on the scientific knowledge we have about indoor air pollutants to be set by the various Member States.

AV: You were mentioning the different ventilation types and systems. In terms of mechanical ventilation, how would that play a role?

PC: State of the art ventilation systems, such as demand control ones, renew the indoor air to the level which is exactly needed. It avoids unnecessary thermal loses which would otherwise increase quite significantly the energy consumption of the building. Typically, when the air is renewed through window opening, massive thermal losses happen. Depending on the conditions, a demand control ventilation can reduce the consumption of a dwelling between 18 to 26%. The French administration has evaluated the potential with the French building stock and have come to the figure 632  TWh of savings in 17 years which is the average lifetime of a ventilation system. Heat and cold exchanger also recover energy by preheating and pre cooling the incoming air and thus additionally reducing the energy need of the building.


Driss Samri (DS), Head of the Health and Comfort Operational Division at the French Scientific and Technical Centre for Buildings (CSTB)

The French Indoor Air Quality Observatory was created in 2001 by the French government with the objective to coordinate and develop air research activities at a national scale. The goals were to improve knowledge on indoor air quality in buildings by collecting data. The purpose was that this knowledge be used for creating public policies and for publishing recommendations for professionals and the general public. The Observatory is funded only by public actors today but there are thoughts on associating with the private sector to have more impact.

The Observatory organises nationwide monitoring campaigns to measure indoor air pollution and collect descriptive data from buildings. It conducts specific studies on specific question, for instance regarding indoor air quality during the COVID pandemic. It makes regular review of the literature and collect of indoor air quality measurement and share the results during local, national and international conferences.

The studies have organised six programs focused on dwellings, school and day-care centres, office buildings, low-energy buildings, hospitals and elderly homes, and communication, training and education.

As an example, it conducted the School Nationwide Survey from 2013 to 2017. It selected more than 300 schools in rural and urban zones with differing climates to measure thermal, acoustic, luminous and air quality factors to give an oversight of the IEQ in schools. It observed that only 25% of the schools posses a mechanical ventilation system. 40% have at least a classroom with a very high ICONE index. The ICONE index is correlated to the amount of CO2 generated in a room which has a negative impact on cognitive performance and on the well-being and health of children.

Under the framework of the European project ALDREN, the observatory also developed a tool named TAIL (for Thermal, Acoustic, Indoor and Luminous environmental quality) in order to rate the IEQ. One of the objective is to check whether the IEQ is degraded when renovation of buildings is made. An index has been made to use in offices and hotels, but the plans are to create an index for the schools.

There is a need to a have a good balance between energy performance and IEQ, for improving buildings’ energy efficiency may reduce air change rate and compromise indoor air quality. It is the reason why the Observatory has created in 2019 a nationwide programme named QSE with the aim to have a better understanding of the IEQ before and after deep energy retrofit. What is interesting about this program is that it enables to develop a simplified and affordable method based on indoor air quality sensors. There exist now a protocol to measure the overall performance of a building before and after its renovation. The objective is to deploy this method in France.


  • Are beauty/aesthetics/design also factors in health and quality of life? Perhaps in a different way ? For better or worse, it’s what households often prioritise.

OG: It is definitely something that people look at. When making decisions about what need to be installed, people often look at the costs and also the design and the beauty of the object.

  • User information would be a first step. We should implement mandatory indicators for IEQ in EPC of the building.

AV: Everyone here probably agrees with this statement. However, we need to make sure that the EPC remains understandable for the user. Information is crucial in terms of raising awareness but we need to convey that in a manner that is understood.

  • What criteria should be measured for indoor air quality? COV, dust, CO2, relative humidity? Which upper and lower limits are considered ideal?

PG: The WHO has a list of pollutants that we can address. It could be our reference for a start.

  • What is the speakers’ assessment of the need for training and skills to have the workers needed to carried out the installations and monitoring?

AV: A lot can be done automatically with sensors, automatic default detection and remote monitoring. Nevertheless, we need more people to size the equipment, to install it correctly and to maintain it. There is a lot of need of skilled personnel to scale up the buildings.

PC: For these competencies to be developed, there needs to be a market for people to work in this field. The regulatory requirements have a strong role to play in creating this market. As an example, in the new French building regulation, we now have to check ventilation systems in new buildings. What we see is that many people started taking this ventilation courses to be qualified to deliver on this requirement. Regulations now push people to be more competent since they did not see the need to do it before.

OG: With smartness, we also need to drive a life-long learning and keep up-to-date on what is possible and what is next, and how we deliver this potential.

PG: Smartness should be used as a tool to help rather than a tool to solve. Problems need to be solved at the personal level. We need authorised personnel to do it, but it can only be done by market which is driven by regulations.

  • Would it be possible to share more information about the indoor air quality campaign currently ongoing in dwellings in France?

DS: Since it is ongoing, we are only collecting data. We currently have the measurements for 500 dwellings but we have not yet exploited the data. The results will be communicated next year.


What clearly came across is that we need a holistic approach. It means that we cannot look at things in isolation.  Decarbonisation, energy-efficiency or IEQ need to be dealt with together with the help of the right technology, the right controls and automation systems. The need has been expressed to draw more awareness of the importance of ventilation in space because it did not get much attention in the past. We need enough and skilled people that can carry out the work that is needed. By doing all this, we will make our buildings a fabulous place, and contribute to achieve the climate goals. One should not forget than buildings represent 40% of greenhouse gases emissions in Europe. Whatever we do must never compromise the reduction of GHG emissions.