MONTANA IRC ADOPTION
X – Effective Statewide
Window Well Requirements For Egress
Without an Egress Ladder
With a Permanent Egress Ladder
Basement Window Requirements For Egress
January 1, 2020 was the statewide effective date established by the California Building Standards Commission (CBSC) for the 2019 California Building Standards Code which adopts the 2018 editions of the IBC, IFC, IRC and IEBC with amendments.
Last updated: Tuesday, March 14, 2022
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Basements. Habitable attics and every sleeping room shall have at least one operable emergency escape and rescue opening. Where basements contain one or more sleeping rooms, emergency egress and rescue openings shall be required in each sleeping room. Where emergency escape and rescue openings are provided they shall have a sill height of not more than 44 inches (1118 mm) measured from the finished floor to the bottom of the clear opening. Where a door opening having a threshold below the adjacent ground elevation serves as an emergency escape and rescue opening and is provided with a bulkhead enclosure, the bulkhead enclosure shall comply with Section R310.3. The net clear opening dimensions required by this section shall be obtained by the normal operation of the emergency escape and rescue opening from the inside. Emergency escape and rescue openings with a finished sill height below the adjacent ground elevation shall be provided with a window well in accordance with Section R310.2.Emergency escape and rescue openings shall open directly into a public way, or to a yard or court that opens to a public way.
Exception: Basements used only to house mechanical equipment and not exceeding a total floor area of 200 square feet (18.58 m2).
All emergency escape and rescue openings shall have a minimum net clear opening of 5.7 square feet (0.530 m2).
Exception: Grade floor openings shall have a minimum net clear opening of 5 square feet (0.465 m2).
The minimum net clear opening height shall be 24 inches (610 mm).
The minimum net clear opening width shall be 20 inches (508 mm).
Emergency escape and rescue openings shall be operational from the inside of the room without the use of keys, tools, or special knowledge.
The minimum horizontal area of the window well shall be 9 square feet (0.9 m2), with a minimum horizontal projection and width of 36 inches (914 mm). The area of the window well shall allow the emergency escape and rescue opening to be fully opened.
Exception: The ladder or steps required by Section R310.2.1 shall be permitted to encroach a maximum of 6 inches (152 mm) into the required dimensions of the window well.
Window wells with a vertical depth greater than 44 inches (1118 mm) shall be equipped with a permanently affixed ladder or steps usable with the window in the fully open position. Ladders or steps required by this section shall not be required to comply with Sections R311.7 and R311.8. Ladders or rungs shall have an inside width of at least 12 inches (305 mm), shall project at least 3 inches (76 mm) from the wall, and shall be spaced not more than 18 inches (457 mm) on center vertically for the full height of the window well.
Window wells shall be designed for proper drainage by connecting to the building’s foundation drainage system required by Section R405.1 or by an approved alternative method.
Exception: A drainage system for window wells is not required when the foundation is on well-drained soil or sand-gravel mixture soils according to the United Soil Classification System, Group ISoils, as detailed in Table R405.1.
Bulkhead enclosures shall provide direct access to the basement. The bulkhead enclosure with the door panels in the fully open position shall provide the minimum net clear opening required by Section R310.1.1. Bulkhead enclosures shall also comply with Section R3184.108.40.206,
Bars, grilles, covers, screens, or similar devices are permitted to be placed over emergency escape and rescue openings, bulkhead enclosures, or window wells that serve such openings, provided the minimum net clear opening size complies with Sections R310.1.1 to R310.1.3, and such devices shall be releasable or removable from the inside without the use of a key, tool, special knowledge or force greater than that which is required for normal operation of the escape and rescue opening.
Emergency escape windows are allowed to be installed under decks and porches provided the location of the deck allows the emergency escape window to be fully opened and provides a path not less than 36 inches (914 mm) in height to a yard or court.
Download the State Local Codes Chart PDF to determine which International Residential Code your state follows. Depending on your State, your local county may have additional/different requirements. Please refer to your local government website for up-to-date information and to confirm the information on this page.