Colorado Egress Window Code
A window must meet certain requirements to pass the state of Colorado’s egress window code. This building code ensures inhabitants have a second means of exit from a basement living space, in the event of an emergency.
Make sure that your new egress window complies with the basement egress window code in Colorado by using our Egress Window Calculator and by purchasing from a trusted company like The Great Egress Company.
What are the Colorado Egress Window Requirements?
- The window must be openable from the inside without the use of keys, tools, or special knowledge.
- If there is more than one sleeping room in a basement, a means of egress is required in each sleeping room.
- It must provide an unobstructed opening with a minimum area of 5.7 sq. ft. (This requirement drops to 5 sq. ft. for grade floor or below grade openings).
- The height of the clear opening must be at least 24" and the width must be at least 20".
- The sill height must not be more than 44" above the floor.
- If the sill height is below grade, the window must have a window well.
- If required, the window well must be at least 9 sq. ft. in an area with a horizontal projection and a width of at least 36" each.
- Window wells deeper than 44" must have permanent steps or a ladder that do not impede the opening of the window.
What are Egress Windows?
Egress means to go out. Egress windows are windows you can use to leave your home. While they may seem like a regulatory burden, these windows furnish occupants with natural light, provide a source of ventilation, and can become a lifesaver in an emergency.
For example, if there is a fire in your home, a single stairwell may become unusable, leaving family members and tenants without a clear path to safety. For bedrooms on floors with multiple doors that lead directly outside, these windows are not strictly necessary. This is because there are clear escape routes that can be taken in the case of an emergency.
In basements, egress windows are essential and, if there is a bedroom, they are required by law in the State of Colorado.
The Colorado Residential Code
Section R310: Emergency Escape and Rescue Openings.
R310.1 Emergency escape and rescue opening required.
Basements, habitable attics, and every sleeping room designated on the construction documents shall have not less than one operable emergency escape and rescue opening. Where basements contain one or more sleeping rooms, an emergency escape and rescue opening shall be required in each sleeping room. Emergency escape and rescue openings shall open directly into a public way, or to a yard or court having a minimum width of 36" that opens to a public way.
Exceptions:
- Storm shelters and basements used only to house mechanical equipment not exceeding a total floor area of 200 sq. ft.
- Where the dwelling unit or townhouse unit is equipped with an automatic sprinkler system installed in accordance with Section P2904 sleeping rooms in basements shall not be required to have emergency escape and rescue openings provided that the basement has one of the following:
2.1 One means of egress complying with Section R311 and one emergency escape and rescue opening.
2.2 Two means of egress complying with Section R311. - A yard shall not be required to open directly into a public way where the yard opens to an unobstructed path from the yard to the public way. Such a path shall have a width of not less than 36".
R310.1.1 Operational constraints and opening control devices.
Emergency escape and rescue openings shall be operational from the inside of the room without the use of keys, tools or special knowledge. Window opening control devices and fall prevention devices complying with ASTM F209 shall be permitted for use on windows serving as a required emergency escape and rescue opening and shall not be more than 70" above the finished floor.
R310.2 Emergency Escape And Rescue Openings.
Emergency escape and rescue openings shall have minimum dimensions in accordance with Sections R310.2.1 through R310.2.4.
R310.2.1 Minimum Size.
Emergency and escape rescue openings shall have a net clear opening of not less than 5.7 sq. ft.
Windows A and B meet all of the area and dimensions requirements and would pass egress in Colorado. Window C, while meeting the dimension requirements, does not meet the area requirement and would not pass egress.
Exception: The minimum net clear opening for grade-floor emergency escape and rescue openings shall be 5 sq. ft.
Windows D and E meet all of the area and dimensions requirements for floor grade and below grade window openings in Colorado.
R310.2.2 Minimum Dimensions.
The minimum net clear opening height dimension shall be 24". The minimum net clear opening width dimension shall be 20". The net clear opening dimensions shall be the result of normal operation of the opening.
R310.2.3 Maximum Height From Floor.
Emergency escape and resume openings shall have the bottom of the clear opening not greater than 44" above the floor.
R310.2.4 Emergency Escape And Rescue Openings Under Decks And Porches.
Emergency escape and rescue openings installed under decks, porches and cantilevers shall be fully openable and provide a path not less than 36" in height and 36" in width to a yard or court.
R310.3 Emergency Escape And Rescue Doors.
Where a door is provided as the required emergency escape and rescue opening, it shall be a side-hinged door or a sliding door.
R310.4 Area Wells.
An emergency escape and rescue opening where the bottom of the clear opening is below the adjacent grade shall be provided with an area well in accordance with Sections R310.4.1 through R310.4.4.
R310.4.1 Minimum Size.
The horizontal area of the area well shall be not less than 9 sq. ft., with a horizontal projection and width of not less than 36". The size of the area well shall allow the emergency escape and rescue opening to be fully opened.
Exception: The ladder or steps required by Section R310.4.2 shall be permitted to encroach not more than 6" into the required dimensions of the area well.
R310.4.2 Ladder and Steps.
Area wells with a vertical depth greater than 44" shall be equipped with an approved, permanently affixed ladder or steps. The ladder or steps shall not be obstructed by the emergency escape and rescue opening where the window or door is in the open position. Ladders or steps required by this section shall not be required to comply with Section R311.7.
R310.4.2.1 Ladders.
Ladders and rungs shall have an inside width of not less than 12", shall project not less than 3" from the wall and shall be spaced not more than 18" on center vertically for the full height of the area well.
R310.4.2.1 Steps.
Steps shall have an inside width of not less than 12", a minimum tread depth of 5" and a maximum riser height of 18" for the full height of the area well.
R310.4.3 Drainage.
Area wells shall be designed for proper drainage by connecting to the building’s foundation drainage system required by Section R405.1
Exception: A drainage system for area wells is not required where the foundation is on well-drained soil or sand-gravel mixture soils in accordance with United Soil Classification System, Group I Soils, as detailed in Table R405.1.
R310.4.4 Bars, grilles, covers and screens.
Where bars, grills, covers, screens or similar devices are placed over emergency escape and rescue openings, bulkhead enclosures or area wells that serve such openings, the minimum net clear opening size shall comply with Sections R310.2 through R310.2.2 and R310.4.1. Such devices shall be releasable or removable from the inside without the use or a key or tool or force greater than required for the normal operation of the escape and rescue opening.
R310.5 Replacement windows for emergency escape and rescue openings.
Replacement windows installed in buildings meeting the scope of this code shall be exempt from Sections R310.2 and R310.4.4, provided that the replacement window meets the following conditions:
- The replacement window is the manufacturer’s largest standard size window that will fit within the existing frame or existing rough opening. The replacement window is of the same operating style as the existing window or a style that provides for an equal or greater window opening area than the existing window.
- The replacement window is not part of a change of occupancy.
R310.6 Dwelling Additions.
Where dwelling additions occur that contain sleeping rooms, an emergency escape and rescue opening shall be provided in each new sleeping room. Where dwelling additions occur that have basements, an emergency escape and rescue opening shall be provided in the new basement.
Exceptions:
- An emergency escape and rescue opening is not required in a new basement that contains a sleeping room with an emergency escape and rescue opening.
- An emergency escape and rescue opening is not required in a new basement where there is an emergency escape and rescue opening in an existing basement that is accessed from the new basement.
- An operable window complying with Section 310.7.1 shall be acceptable as an emergency escape and rescue opening.
R310.7 Alterations Or Repairs Of Existing Basements.
New sleeping rooms created in an existing basement shall be provided with emergency escape and rescue openings in accordance with Section R310.1. Other than new sleeping rooms, where existing basements undergo alterations or repairs, an emergency escape and rescue opening is not required.
Exception: An operable window complying with Section 310.7.1 shall be acceptable as an emergency escape and rescue opening.
R310.7.1 Existing emergency escape and rescue openings.
Where a change of occupancy would require an emergency escape and rescue opening in accordance with Section 310.1, operable windows serving as the emergency escape and rescue opening shall comply with the following:
- An existing operable window shall provide a minimum net clear opening height of 22" and a minimum net clear opening width of 20".
- A replacement window where such window complies with both of the following:
2.1 The replacement window meets the size requirements in Item 1.
2.2 The replacement window is the manufacturer’s latest standard-size window that will fit within the existing frame or existing rough opening. The replacement window shall be permitted to be of the same operating style as the existing window or a style that provides for an equal or greater window opening area than the existing window.
Complying With Colorado Egress Window Code
To put it simply, if you are renovating your basement in Colorado, you will need an egress window that has a wide clearance and can be easily opened.
The Great Egress Company provides a curated collection of windows that meet egress window requirements in Colorado. The easiest way to get your hands on a code-compliant egress window is to let us ship one straight to your door. Have a look for yourself.
Our windows come in several types and sizes that will pass the egress window code in Colorado. Contact our team if you have additional egress window questions.
