Functional Statement:


To minimize the risk of inadequate performance due to improper maintenance or lack of maintenance.


OH1.1, OH1.2



Access openings for crawl spaces whose exterior walls have less than 25% of their total area above exterior ground level open to the outdoors, in buildings to which Part 9 applies [see Sentence of Division A for application of Part 9].


To limit the probability of an inability to inspect conditions or services in crawl spaces, which could lead to:
  • malfunctioning or inoperable building services, or
  • the ingress of water from the ground going undetected.
This is to limit the probability of:
  • an inadequate control of the temperature of interior spaces, relative humidity or the accumulation of moisture,
  • inadequate ventilation,
  • the production of hazardous by-products of combustion,
  • the generation of pollutants from biological growth or from materials that become unstable on wetting, or
  • deterioration, which could lead to compromised integrity of environmental separators or of elements protected by the separators.
This is to limit the probability of:
  • negative effects on the air quality of indoor spaces, and
  • the inadequate thermal comfort of persons.
This is to limit the probability of harm to persons.