Precondition (mandatory for certification). Outdoor air is supplied to dilute pollutants: mechanically ventilated systems are designed (or, if existing, tested and balanced within five years) to a recognised ventilation standard (ASHRAE 62.1 or 62.2, EN 16798-1, AS 1668.2 or CIBSE Guide A) covering at least 90% of the area; naturally ventilated buildings follow a natural ventilation procedure, keep the relied-on openings open or controlled during occupancy and have acceptable outdoor particulate levels (a higher-particulate option caps certification at Silver); or carbon dioxide is held at 900 ppm or below, or within 500 ppm of outdoors. Parts: Ensure Adequate Ventilation.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.