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IBC Section 1012 — Natural Light and Ventilation

Updated Apr 3, 2026
Establishes requirements for windows and natural ventilation to improve occupant wellbeing.

Section 1012 requires that occupied spaces have access to natural light through windows. Window area is typically 10 percent of floor area minimum. North-facing spaces may require larger windows. Occupied spaces also require ventilation either natural through operable windows or mechanical systems. Natural ventilation opening areas are calculated based on floor area.

TAGS
ibcnatural-lightventilation
DETAILS
section
1012
category
Means of Egress
code body
IBC
code year
2021
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