Let science speak for itself – Systemic challenges with implementing adequate ventilation in schools – Part 2
Here is a vital collection of insights and valuable knowledge from the gathering of scientists, researchers and practitioners on the topic of indoor air quality – not only in schools. In the last Update and Insight, the invisible problem of air in schools with health and cognitive impacts were explored. In this second part, ventilation in schools is presented not only as a technology problem but also as an implementation problem due to systemic barriers and challenges.
The biggest barrier to implementing proper ventilation in schools is not technical; it requires systemic changes in incentives and regulations, public-sector involvement, and the role of users, including monitoring.
"Ventilation is based solely on the goodwill of the people in the room. Even with educated teachers, the thresholds are not respected." – Valérie Leprince. Project Director for Ventilation and Indoor Environmental Quality. CEREMA (Center for Studies and Expertise on Risks, the Environment, Mobility and Planning).
- French regulations impose ventilation rates of 15 m³/h per student, which is half the European recommendations of 30 m³/h. Furthermore, only 15% of French schools were equipped with mechanical ventilation systems, which were often poorly maintained and rarely tested.
- The importance of regular verification of systems performance and the welcomed 2024 European directive, which introduced a requirement for inspections every 3 to 5 years.
- While the installation of mechanical ventilation systems can be costly (€3,000 to €5,000 per class), it offers a return on investment through energy savings (€6 to €7 per student per year) and measurable health benefits.
"A school must document its ventilation system and plan a strategy for the use of and adjustments to devices in the event of an emerging health risk." – Benjamin Jones, Associate Professor, Department of Architecture and the Built Environment, University of Nottingham
- Different types of ventilation systems are used: natural ventilation, simple mechanical ventilation and hybrid systems combining the two, with complementary devices such as platform fans for thermal comfort. User interaction is essential, and the systems must be easy to understand and control. Furthermore, it is important to ensure proper long-term maintenance through contracts.
- Drafting a new standard (H251) related to pandemic preparedness, which establishes minimum requirements to limit the transmission of infectious aerosols in indoor environments. This by emphasising compliance with basic air quality standards. It requires establishments to have a ventilation management and control plan, as well as a strategy for adapting the system in the event of a health risk (e.g, effective filtration, UV disinfection, reduction of occupancy rate). This approach allows buildings with limited ventilation capacities to remain compliant.
"We must prepare for a transition that is not a revolution, but an incremental approach. In Belgium, only 15% of school buildings have mechanical ventilation, the majority relying on window ventilation. The main challenge, therefore, is a massive renovation to ensure adequate ventilation." – Jelle Laverge, Associate Professor in the Building Physics Research Group of the Department of Architecture and Urban Planning at Ghent University
"Prevention is not within the biomedical field... it will require investments from a very wide variety of sources." – Dominique Costagliola, Emeritus Research Director at Inserm (Pierre Louis Institute of Epidemiology and Public Health), and Member of the Academy of Sciences
- Preventing indoor air quality issues in schools is a complex challenge. It requires the mobilisation of a large number of diverse stakeholders, such as local authorities, departments, and regions, who are responsible for investments made. However, these stakeholders do not necessarily see the benefits of these investments, which primarily translate into gains in public health and savings on healthcare costs. This gap between the investor and the beneficiary outcomes makes it difficult to attract funding.
- The importance of implementing a monitoring system that not only measures improvements in indoor air quality after interventions, but also assesses the positive impacts on occupant health, must be clear. This assessment is essential for justifying investments and guiding future actions.
"The main thing is certainly to involve all the school users." – Enric Robine, Director of the Pandemic and Built Environments Program, CSTB
- When the need to take action on indoor air quality is no longer a matter of debate. The real question is how to achieve it in practice.
- Given the risk of future pandemics, there is a need to better understand the transmission of airborne pathogens and how long they remain in the environment. This is in order to anticipate risks and propose rapid responses. The challenge is twofold: to limit the emergence of new pathogens through better environmental control (zoonoses, air quality) and to prepare for future crises by strengthening research and innovation (R&I) and sharing information on environmental countermeasures. This is without waiting for therapeutic tools and vaccines, which might be slow to develop.
"It is people and users who are driving the transformation." – Gaëlle Guyot, Deputy Head of the High-Performance Buildings Research Team, Center for Studies and Expertise on Risks, the Environment, Mobility and Planning (CEREMA)
- The new European directive on the inspection of ventilation systems in commercial buildings. In France, one in two ventilation systems malfunctions, often due to poor installation. The mandatory inspections already required for residential buildings could be extended, with a beneficial effect: the cost of this measure for the community would be offset by improved building performance, which avoids the expenses of technical failures.
- There is no technological magic wand. A coherent set of simple actions, good practices, research, communication and regulation will make it possible to sustainably improve indoor air quality in buildings.
"Ventilation is an investment, not just an expense." – Cécile Philippe, President of the Molinari Economic Institute
"Students at school need to be safe. That’s all." – Mélanie Heard, General Delegate of Evidences, Head of the health center at Terra Nova
- In the case of indoor air quality, the problem is multi -faceted: industrial pollution, unsanitary conditions, thermal comfort, public health, child protection, energy and environmental protection. Many issues overlap and are complete - housing, education, health, the environment, etc. This makes creating a shared vision essential.
- Political discourse plays a crucial role here in determining which values should guide collective action: keeping children safe in school, overall public health, building safety, or energy and environmental objectives. This choice is fundamental because it determines the priorities to be set and the resources available.
More information about the conference
On June 20th, 2025, the 2nd European Conference on Indoor Air Quality: French Schools was jointly organised by a collective of seven organisations: the Geneva Health Forum (GHF), the Institute for Global Health (ISG), the Centre for Studies and Expertise on Risks, Environment, Mobility and Planning (Cerema), the Ecoles et familles oubliés (EFO) Collective, the Molinari Economic Institute, the Nous aérons Collective and the Scientific and Technical Centre for Building (CSTB).
