1. OH1
  2. OS2
  3. OS1
  4. +


OH1 Indoor Conditions


[F81-OH1.1]Applies to windows that provide required non-heating season ventilation.


Intent 1:

To limit the probability that the performance of windows, doors and skylights will fall significantly below expectations with respect to:

  • resistance to air pressure loads,
  • resistance to structural loads,
  • resistance to water penetration loads,
  • resistance to snow loads on skylights or where windows have sloped or near-horizontal components,
  • resistance to forced entry, and
  • ease of operation.

This is to limit the probability of:

  • excessive air leakage,
  • excessive heat loss or gain,
  • condensation,
  • precipitation and melt water ingress,
  • insufficient protection against the ingress of insects and vermin, or
  • inoperability or excessive difficulty in operating doors and openable windows.

This is to limit the probability of:

  • the inadequate control of temperatures of interior spaces, relative humidity, drafts, or water accumulation,
  • the generation of pollutants from biological growth or from materials that become unstable on wetting,
  • deterioration, which could lead to compromised integrity of exterior wall assemblies, or
  • inadequate ventilation where windows, doors and skylights provide required non-heating-season ventilation.

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.

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