In this blog post I’m going to discuss and describe some of the requirements for Emergency Escape and Rescue Openings, often just called an egress window. But keep in mind that these details are enforced only in jurisdictions that use the International Residential Code (IRC). That includes almost all of the cities and towns in the Chicagoland area (and most of the cities throughout the United States), but it doesn’t include Chicago itself. Chicago goes in a different direction with its residential property codes. You can look at the addendum at the end of this blog post for a brief explanation of these differences, but for now just realize that Chicago has different rules.
The IRC in section 310.1 says “Basements, habitable attics and every sleeping room 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 inches that opens to a public way.” There are some exceptions: A very small basement (200 square feet or less used only to house mechanical equipment) doesn’t require an emergency escape and rescue opening. And if the house is equipped with an automatic fire sprinkler system then a sleeping room in the basement isn’t required to have an emergency escape and rescue opening as long as the basement has either: one standard means of egress (for example, up the stairs and out the front door) and one emergency escape and rescue opening somewhere else in the basement, or two standard means of egress.
Let’s unpack this a little bit.
- All basements require a way out, directly to the outside (public way) – either a door or window.
- All bedrooms (sleeping rooms) require a way out, directly to the outside – either a door or window.
- If the bedroom is in the basement then that door/window can serve the entire basement.
- The rules for basement bedrooms are a little different if there’s a fire sprinkler system, but you definitely need two ways out of the house.
Of course the window has to be big enough for you to get out (that’s the “escape” part), and it has to be big enough for a fire fighter to get in (that’s the “rescue” part of emergency escape and rescue opening). Here are the rules for the size of the window used as an emergency escape and rescue opening.
The IRC in section 310.2.1 it says “Emergency escape and rescue openings shall have a net clear opening of not less than 5.7 square feet. Exception: The minimum net clear opening for grade-floor emergency escape and rescue openings shall be 5 square feet.”
So the window has to open completely to a size of 5.7 square feet, or 5 square feet if it’s at grade-floor level. The IRC defines grade floor here as meaning that the bottom of the window opening is not more than 44 inches above or below the ground level just outside of the window.
The IRC goes on to say in section 310.2.2 “The minimum net clear opening height dimension shall be 24 inches. The minimum net clear opening width dimension shall be 20 inches. The net clear opening dimensions shall be the result of normal operation of the opening.”
So the window has to open to at least 24 inches high and 20 inches wide. But of course these dimensions don’t produce an opening of 5.7 square feet, so at least one of these dimensions has to be bigger. For example, at 24 inches high you’d need 34.2 inches wide to get to 5.7 square feet. And at 20 inches wide you’d need 41.04 inches high to get there.
The IRC also says in section 310.2.3 “Emergency escape and rescue openings shall have the bottom of the clear opening not greater than 44 inches above the floor.”
Again let’s unpack this a little bit. A window used for an emergency escape and rescue opening must be:
- minimum of 5.7 square feet, or 5 square feet at grade level
- at least 24 inches high net clear opening
- at least 20 inches wide net clear opening
- at most 44 inches high from the finished floor to the clear opening
One more thing to mention here is that if this window opens up into a window well that’s more than 44 inches deep then that window well needs a permanently attached ladder. You don’t want someone to get out of the house but be stuck in a window well.
I’ve had a hard time trying to determine when the requirements for emergency escape and rescue openings first became a code requirement. Certainly in the 1950’s and earlier this just wasn’t a thing, and many houses I see from this era and earlier don’t have any type of exit from the basement directly to the outside and don’t have properly sized bedrooms windows. That’s just part of the fun of buying an older house. But depending on how you plan to use your basement it’s something that you might want to consider. In most cases you’d need to remove one of the existing windows, cut down the foundation wall, and install a bigger window and probably a window well. This can be quite expensive. And please don’t let anyone cut your foundation unless you’re absolutely sure they know what they’re doing.
How can you determine if a room is a “sleeping room” and needs an emergency escape and rescue opening? I don’t know. The International Residential Code doesn’t define “sleeping room”, so this part of the code can be open to interpretation. The question I like to ask my clients is whether or not the seller is claiming this as a bedroom. If the seller is marketing the house as having four bedrooms, and there are three bedrooms upstairs and this room in the basement, then I think it pretty clearly should have the proper emergency escape and rescue opening. Or the seller should change the listing to three bedrooms.
And course, what to do if you’re in Chicago and none of this applies? Emergencies don’t know from city boundaries, so you’ll just have to accept that your house doesn’t meet the code requirements that the rest of Chicagoland does. If there are two ways out of the house that’s certainly a good start towards safety, and it would be a good idea to keep a fire extinguisher handy, but that’s certainly no guarantee of anything. And be extra sure that your smoke and carbon monoxide alarms are in good condition to give yourself as much notice as possible of a problem.
Addendum: Chicago code versus suburban codes
The vast majority of cities and towns and villages in the Chicagoland area (and throughout the United States) enforce the International Residential Code for single family homes and townhouses. Some enforce older versions (the IRC is updated every three years) and some have started enforcing newer versions, but it’s still the International Residential Code at the core. The IRC is part of the model codes written by the International Code Council. These include the International Building Code, the International Fire Code, the International Fuel Gas Code, the International Existing Building Code, the International Energy Conservation Code, the International Private Sewage Disposal Code, the International Swimming Pool and Spa Code, the International Wildland Urban Interface Code, the International Zoning Code, the International Property Maintenance Code, the International Performance Code for Buildings and Facilities, the International Plumbing Code, the International Mechanical Code, the International Green Construction Code. You get the idea – very comprehensive. (By the way, the National Electrical Code is written by the National Fire Protection Association NFPA.)
Generally speaking cities that use the International Codes enforce the International Building Code for large commercial buildings and larger multi-family buildings, and they enforce the International Residential Code for one- and two-family buildings and attached townhouses.
But the City of Chicago goes in a different direction. For a long time Chicago enforced its very own building code, covering the physical structure as well as the utilities like electrical and plumbing. And Chicago only had one code book to cover all its buildings, from large commercial buildings to small residential single family homes. In 2015 Chicago began the process of switching from using their own codes to using these model codes from the International Code Council. Chicago still uses its own code book, but it’s aligned very closely with the IBC.
But – there’s always a “but” when dealing with Chicago – the city is still using only one code book. They’re using only the International Building Code now, and not the International Residential Code. Chicago very deliberately chose to stick with just one code book for all buildings, from the Sears Willis Tower to small little single family bungalows. And Chicago chose very deliberately to not include any of the IRC’s provisions for emergency escape and rescue openings in its codes. The given reason is that Chicago’s land use – the way it locates houses on various plots of land – just doesn’t allow for this type of emergency escape and rescue opening in many cases. So they don’t require it.
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