France

French regulation regarding residential ventilation dates from 1982. Almost every new residential buildings constructed since then are equipped with a mechanical ventilation system. 
For non-residential buildings, the regulation dates from 1979 and does not impose the installation of a ventilation system as a prescriptive requirement. Nevertheless, if air renewal relies only on windows opening, a significant windows area is necessary (according to the floor area) for the building to be considered compliant with the regulation. 
 

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:

In France, in Residential buildings, since 1982 the ventilation regulation imposes air flow rate to be continuously extracted from every room with humidity production. A boosted level of air flow rate shall be reachable in the kitchen. Since the mid-80s demand-controlled ventilation based on humidity level in each room has been allowed, provided that the system is validated by a national commission. In practice, for 40 years every new residential building has a mechanical ventilation system and 95% of them are centralised extract only systems.

By using natural driving forces, hybrid ventilation systems reduce fan energy consumption in buildings. They are of increasing interest as they help to improve buildings energy efficiency while ensuring good indoor environmental quality. However, the performance of these systems is variable and dependent on climatic conditions. Besides, the plurality of openings, variable airflows, and unstable flow patterns make the measurement of the performance of natural or hybrid ventilation systems a challenging task.

The AIVC is preparing a series of VIP on national regulations and trends in airtightness for various countries (numbered VIP 45.XX), detailing for both building and ductwork airtightness: 

The current French EP regulation called “RT 2012” imposes a maximum airtightness level2 of residential buildings envelope: 0.6 m³.h^-1.m^-2 for single-family houses and 1 m³.h^-1.m^-2 for multi- family buildings. The respect of these requirements must be justified either with an airtightness test of each building or by the application of a certified quality management approach on the building airtightness. In both cases, airtightness tests must be performed by a third-party tester, qualified by the certification body, Qualibat.

Demand controlled ventilation systems are representing a large majority of installations in France. They are commonly used for more than 35 years. The strong development of these systems can be explained by the French regulatory framework for air renewal. These demand controlled systems have been developed in order to optimise the energy consumption and at the same time to ensure indoor air quality and building durability. In residential buildings, demand control is based mainly on humidity whereas in commercial buildings it is based on occupancy and/or CO2 levels.