Intent 1:
To limit the probability of a discontinuous air
barrier system at penetrations through assemblies, which could lead
to a loss of airtightness, which could lead to: 
- excessive heat loss or gain due to air mass transfer,
 - excessive air infiltration and exfiltration,
 - excessive airborne vapour transfer from interior above
ground and exterior below ground, or
 - precipitation ingress due to air pressure differences.
 
This is to limit the probability of: 
- an inadequate control of the temperature of interior
spaces, drafts, indoor relative humidity, or water accumulation,
 - pollutant ingress from the exterior, including combustion
products from parking garages, or particulates, 
 - the generation of pollutants from biological growth
or from materials that become unstable on wetting, or 
 - deterioration, which could lead to compromised integrity
of assemblies acting as or protected by environmental separators.
 
This is to limit the probability of: 
- negative effects on the air quality of indoor spaces, 
 - the inadequate thermal comfort of persons, and 
 - contact with moisture.
 
This is to limit the probability of harm to persons.