Methodology to define new performance indicator for ventilation regulation in France

In France, the regulation context for ventilation is based on the decree « Arreté de 1982 » which is a prescriptive regulation, requiring extracted flowrate in every utility room. These extracted airflow should respond to several principles:

1. The air renewal in dwelling is general and permanent at least during the heating season.
2. The air renewal system shall include natural or mechanical inlet in main rooms and outlet in utility rooms. The air shall circulate between main and utility rooms
3. The ventilation system shall be able to reach, simultaneously or not a set of prescribed flowrates by room with exhaust, function of the type of the room and the size of the dwelling
4. The total extract flowrate can be reduced with a minimal flowrate to be respected
5. (function of the number of main rooms)
6. The air inlet shall be designed to reach the prescribed flowrates in utility rooms.

These principles were strong basis to generalise mechanical ventilations in residential building to avoid humidity issues and mould growth thanks to these minimal flowrates to be respected. However, it is quite restrictive for other ventilation systems with variable flowrate that could be temporarily lower. Moreover, this decree has no requirement on supply flowrate. As result, lots of existing systems are not compatible with the actual regulation such as supply only system, ventilation per room, system without higher flowrate in the kitchen, and generally more advanced control strategies.  

The new building code « code de la construction » propose an alternative to the prescriptive approach, based on the following statement: « Air renewal, shall be such as, in normal condition of use, the indoor air pollution does not endanger health and security of occupants and that condensation is avoided, except temporarily » 
These new principles in building code for air renewal open the possibility for a range of systems to be compatible with the regulation. But this switch from a prescriptive approach to a performance-based approach need to be adapted in the regulation with a robust methodology to assess the effective performance of ventilation systems. In addition, the requirements for performance should be such as most of system that comply with 1982 requirements fulfil performance requirements.  
The objectives of this work is to define a set of key performance indicator (KPI) for ventilation that are equivalent to the existing prescriptive regulation. Which is ambitious because defining KPI for ventilation is still a matter of research, this is worked on in IEA-EBC Annex 86.