Max height of egress window from finished grade

[jefe024]

Hi all,

Does anyone know the max height an egress window can be from finished grade? I see that a window can be no more than 44 inches from the floor inside, but I’m wondering about the height from the finished grade outside.

Thanks!

 

[ICE]

There is no maximum height above grade unless the net free opening is less than 5.7 square feet and no less than 5 square feet In which case the maximum height above grade is 44”.

R310.2.1 Minimum opening area. Emergency and escape rescue openings shall have a net clear opening of not less than 5.7 square feet (0.530 m2). 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. The net clear height of the opening shall be not less than 24 inches (610 mm) and the net clear width shall be not less than 20 inches (508 mm).
Exception: Grade floor openings or below-grade openings shall have a net clear opening area of not less than 5 square feet (0.465 m2).

GRADE FLOOR OPENING. A window or other opening located such that the sill height of the opening is not more than 44 inches (1118 mm) above or below the finished ground level adjacent to the opening. (See also “Emergency escape and rescue opening.”)

 

[steveray]

You get a break at 4 stories or more I think....When they figure you wont survive and the likelyhood of sprinklers is greater....

 

[fatboy]

New Construction? Existing?

If existing, what year was it built?

 

[steveray]

1030.1 General. In addition to the means of egress required
by this chapter, provisions shall be made for emergency
escape and rescue openings in Group R-2 occupancies in
accordance with Tables 1006.3.2(1) and 1006.3.2(2) and
Group R-3 occupancies. Basements and sleeping rooms
below the fourth story above grade plane shall have at least
one exterior emergency escape and rescue opening in accordance
with this section.

 

[BN4537]

My understanding is that standard firefighter procedure is to throw at least one ladder up on each side of a multistory house when they get on site and begin to attack a fire. This way, firefighters and victims can escape or be rescued from upper stories. If someone has to bail out because of the fire, they can use the ladder to escape, or hang from a window that doesn't have a ladder and someone on the ground can scoop them with the ladder that is already nearby.

If you are over four stories, that whole ladder thing is not nearly as practical or feasible, so the EERO has limited value.

 

[ICE]

Here’s a wrinkle:

R310.2.5 Replacement windows. Replacement windows installed in buildings meeting the scope of this code shall be exempt from the maximum sill height requirements of Section R310.2.2 and the requirements of Section R310.2.1, provided that the replacement window meets the following conditions:
1. The replacement window is the manufacturer's larg- est 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 exist- ing window.
2. The replacement window is not part of a change of occupancy.

 

[Yikes]

jefe024, there's a very specific reason they don't use the word "egress" when describing an Emergency Escape and Rescue Opening
(EERO) : if it were part of an "egress" path of travel, it would have to meet all the usual rules about maximum door threshold height, etc.

On the exterior face of a building, there is no minimum or maximum allowable height from the ground up to the sill of the opening. However:
1. As others have said, an EERO is not required on the 4th floor or higher.
2. Like any other building opening, when the floor inside the building is more than 30" above adjacent grade, a guard is required to keep people from accidentally falling out of the opening. IBC 1030.1.1 allows special window opening control devices meeting ASTM F2090 to be installed. These will normally limit the window to only open <4", meeting the requirements of a guard, while allowing the device to be overridden in an escape or rescue situation.

 

[ICE]

R312.2.1 Window sills. In dwelling units, where the top of the sill of an operable window opening is located less than 24 inches above the finished floor and greater than 72 inches above the finished grade or other surface below on the exterior of the building, the operable window shall comply with one of the following:
1. Operable window openings will not allow a 4-inch-diameter sphere to pass through where the openings are in their largest opened position.
2. Operablewindowsareprovidedwithwindowfallpre- vention devices that comply with ASTM F2090.
3. Operable windows are provided with window opening control devices that comply with Section R312.2.2.

R312.2.2 Window opening control devices. Window opening control devices shall comply with ASTM F2090. The window opening control device, after operation to release the control device allowing the window to fully open, shall not reduce the net clear opening area of the window unit to less than the area required by Section R310.2.1.

R310.2.2 Window sill height. Where a window is provided as the emergency escape and rescue opening, it shall have the bottom of the clear opening not greater than 44 inches measured from the floor; where the sill height is below grade, it shall be provided with a window well in accordance with Section R310.2.3

It is noteworthy that when measuring the maximum height of an EERO from the floor, the measurement is to the bottom of the clear opening but when measuring for fall protection the measurement is from the top of the window sill.

 

[mtlogcabin]

There is no maximum height above grade unless the net free opening is less than 5.7 square feet and no less than 5 square feet In which case the maximum height above grade is 44”.

Since the majority of contractors and SFR designers never read a code book we never give out the 5 sq ft option when asked what size does an EERO need to be.

 

[mtlogcabin]

Here’s a wrinkle:

It is word for word in the IEBC however the IEBC includes R-2 and R-3 occupancies

505.3 Replacement window emergency escape and rescue openings.
Where windows are required to provide emergency escape and rescue openings in Group R-2 and R-3 occupancies and one- and two-family dwellings and townhouses regulated by the International Residential Code, replacement windows shall be exempt from the requirements of Sections 1030.2, 1030.3 and 1030.4 of the International Building Code and Sections R310.2.1, R310.2.2 and R310.2.3 of the International Residential Code, provided that the replacement window meets the following conditions:

1. 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 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.

2. The replacement of the window is not part of a change of occupancy.

Window opening control devices complying with ASTM F2090 shall be permitted for use on windows required to provide emergency escape and rescue openings.

Here’s a wrinkle:

And another IEBC section with no mention of sill height maximum

1011.4.1 Means of egress for change to a higher-hazard category.
Where a change of occupancy classification is made to a higher-hazard category (lower number) as shown in Table 1011.4, the means of egress shall comply with the requirements of Chapter 10 of the International Building Code.

Exceptions:

7. An existing operable window with clear opening area not less than 4 square feet (0.38 m2) and minimum opening height and width of 22 inches (559 mm) and 20 inches (508 mm), respectively, shall be accepted as an emergency escape and rescue opening.

 

[jefe024]

Y’all are awesome! Thanks so much!!!

 

[Mr. Inspector]

Replacement windows for houses in PA don't need any permits or inspections.

 

[Genduct]

My understanding is that standard firefighter procedure is to throw at least one ladder up on each side of a multistory house when they get on site and begin to attack a fire. This way, firefighters and victims can escape or be rescued from upper stories. If someone has to bail out because of the fire, they can use the ladder to escape, or hang from a window that doesn't have a ladder and someone on the ground can scoop them with the ladder that is already nearby.

If you are over four stories, that whole ladder thing is not nearly as practical or feasible, so the EERO has limited value.

Yep, was thinking the same thing you are. How high can the local Fire Dept reach

 

[e hilton]

There is no maximum sill height for emergency escape and rescue openings. Pertinent sections of the
code may be found here R310.2 Emergency Escape and Rescue Openings. Hope that this helps you.

That conflicts with the 3rd para of post #9 by Ice. I’m betting on Ice.

 

[Yikes]

That conflicts with the 3rd para of post #9 by Ice. I’m betting on Ice.

In context, the original post #1 was about sill height above "grade", which I infer to be about height above exterior grade. I think in that context codedocent’s response in post #15 was referring to exterior also.

3rd paragraph in Ice’s post appears to be about the height above floor, which I infer to be the interior side of the opening:
"R310.2.2 Window sill height. Where a window is provided as the emergency escape and rescue opening, it shall have the bottom of the clear opening not greater than 44 inches measured from the floor; where the sill height is below grade, it shall be provided with a window well in accordance with Section R310.2.3".

So, I don’t think there’s a conflict; it’s just looking at the window height from outside vs. inside.

 

[mtlogcabin]

There is no maximum sill height for emergency escape and rescue openings. Pertinent sections of the
code may be found here https://up.codes/viewer/colorado/irc-2021/chapter/3/building-planning#3. Hope that this helps you.

You are correct the IRC and IBC now measures the maximum to the bottom of the clear opening not the window sill as in previous editions

R310.2.3 Maximum Height From Floor

Emergency escape and rescue openings shall have the bottom of the clear opening not greater than 44 inches (1118 mm) above the floor.

 

[rogerpa]

Section R310 of the IBC

You mean Section R310 of the IRC.