Ventilation Building Codes

Indiana

1209.2, Attic spaces, An opening not less than twenty (20) inches by forty (40) inches (five hundred eight (508) mm by one thousand sixteen (1,016) mm) shall be provided to any attic area having a clear height of over thirty (30) inches (seven hundred sixty-two (762) mm). Thirty (30) inches (seven hundred sixty-two (762) mm) minimum clear headroom in the attic space shall be provided at or above the access opening. When the access opening penetrates fire-resistive construction, the attic access opening closure shall provide the fire-resistive construction as required for the fire-resistive construction that is penetrated for the opening, and may be manufactured or field assembled, and shall be tight fitting