Typical Egress Window and Well Detail


Every sleeping room shall have at least one operable emergency escape and rescue window or exterior door opening for emergency escape and rescue. Rooms with a storage closet greater than 18 inches in depth or direct access to a bathroom shall also comply with this requirement. Where openings are provided as a means of escape and rescue, they shall have a clear opening height not more than 44 inches above the floor. The net clear opening dimensions required by this section shall be obtained by the normal operation of the window or door opening from the inside. Escape and rescue window openings with a finished sill height below the adjacent ground elevation shall be provided with a window well in accordance with Section R310.2.

R310.1.1 Minimum opening area: All emergency escape and rescue openings shall have a minimum net clear opening of 5.7 square feet.

R310.1.2 Minimum opening height: The minimum net clear opening height shall be 24 inches.

R310.1.3 Minimum opening width: The minimum net clear opening width shall be 20 inches.

R310.1.4 Operational constraints: Emergency escape and rescue openings shall be operational from the inside of the room without the use of keys, tools or special knowledge.

R310.1.5 Double hung egress window: Double hung windows must meet the requirements for an egress window without removing the upper sash.


R303.1 Habitable rooms: All habitable rooms shall have an aggregate glazing area of not less than 8 percent of the floor area of such rooms. Natural ventilation shall be through windows, doors, louvers or other approved openings to the outdoor air. Such openings shall be provided with ready access or shall otherwise be readily controllable by the building occupants. The minimum openable area to the outdoors  shall be 4 percent of the floor area being ventilated.

R310.2 Window wells: Window wells required for emergency escape and rescue shall have horizontal dimensions that allow the door or window of the emergency escape and rescue opening to be fully opened. The horizontal dimensions of the window well shall provide a minimum net clear area of 9 square feet with a minimum horizontal projection and width of 36 inches. A guard is required when a sidewalk, patio, or driveway is 60 inches or less from an egress window well 30 inches in depth or greater.

EXCEPTION: The ladder or steps required by  Section R310.2.1 shall be permitted to encroach a maximum of 6 inches into the required dimensions of the window well.

R310.2.1 Ladder and Steps: Window wells with a vertical depth greater that 44 inches below the adjacent ground level 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. Ladders or rungs shall have an inside width of at least 12 inches, shall project at least 3 inches from the wall and shall be spaced not more than 18 inches on center vertically for the full height of the window well.