While it is generally accepted that a ventilation system in a building—whether natural, mechanical or hybrid—is needed to provide acceptable indoor air quality and prevent building damage, there are debates about the actual performance of these systems and how the deviations observed affect the overall buildings performance and the well-being or safety and health of the occupants. These debates are increasingly active given the sensitivity of new and renovated buildings on energy use and indoor air quality depending on the field characteristics of ventilation systems.

This is the reason why several initiatives have arisen in the past few years either to characterize ventilation system installation performance in residential buildings or to improve their quality through voluntary or regulatory schemes. This has brought to light questions such as:

• What is the knowledge regarding the quality of ventilation systems in residential buildings in various countries?
• What is the status with existing approaches to improve the quality of these systems?
• What can we learn from targeted efforts to characterize or monitor real ventilation system performance?
• How can quality frameworks help improve the situation and how can they converge with existing regulations or programmes?

A major objective of this workshop was to discuss pros and cons of existing approaches as well as ways to explore to improve the situation with key experts from various countries. A major focus of the presentations was on the schemes developed to secure the quality of the ventilation systems in residential buildings. This entails in particular the development of quality labels and performance display for products, qualification schemes for installers, design and installation guidelines, and training for designers and craftsmen, as well as the implementation of commissioning protocols, maintenance protocols, regular inspections and real performance measurements.

In addition to the workshop proceedings, an expected outcome of the workshop involved a critical review of the pros and cons of the approaches presented during the event, including proposals for improvements.