emergency escape windows.

If the minimum square footage of an escape window is 5.7, HOW are the minimum measurements 20x24??? that’s only 3.3333333sqft…

The window would have to be taller or wider to meet the 5.7 sq ft requirement.

20 and 24 are the minimum.

depends on what your local code says.

You can have a 20" wide that is 5.7 and you can have e 24" high that is 5.7.

That is all the minimums are saying.

It is not giving the overall minimum dimensions.

To properly answer this question, you would really need more information that just a photo - you would also need to know how tall and wide the window opening is, how high the window is off the floor, and how close the window is to the exterior grade. For proper egress, windows must open at least 24? high, 20? wide, and have a net openable area of 5.7 square feet. That’s a large window! This means that if a window only meets the minimum height and width requirements, the net openable area will only be 3.33 square feet (24×20 = 480. 480 / 144 = 3.33). If a window opens 24? high, it would need to be 34.2? wide to meet the minimum opening requirement. Besides the opening requirement, the window also needs to be within 44? of the floor. Below is an excellent diagram that illustrates two different windows that both meet the minimum requirements.


So what about the quiz? The only window that met egress requirements was the last one, F. ’A‘ had a net openable area less that 5.7 sf. ’B‘ was too high above the floor, had less than 5.7 sf of net openable area, and was less than 24? high. ‘C‘ was less than 5.7 sf. ‘D‘ was slightly more than 44? above the floor.

Why do some people label only a basement room with a tiny window a ‘non-conforming’ bedroom, while often none of the windows in the home meet egress? It’s because they don’t know better. Just for the record, there are several more requirements for a window to meet egress, and there are several ways for smaller windows to be ‘conforming’, but the details get… quite detailed. Also, today’s building code no longer uses the term ‘egress window’ - they’re more broadly categorized as Emergency Escape and Rescue Openings. As always, please feel free to email me with any specific questions.

Reuben Saltzman, Structure Tech Home Inspections Home Inspection Minneapolis…

The egress openings should not have a sill height more than 44 inches (1118 mm) above the floor.
Egress openings should have a minimum net clear opening of 5.7 square fee (0.530 square meters). The only exception would be grade level openings which only require 5 square feet (0.465 square meters). Note: Casement windows have less net clear opening than their frames.
The minimum height of an egress opening should be at least 24 inches (610 mm).
The minimum width of an egress opening should be at least 20 inches (508 mm).

Thanks guys. The wording is a little vague. I didn’t realize it was a minimum in one direction or the other.

Yes it is a misleading wording. Now imagine when you say that to a homeowner. Try and stick to the 5.7 sg ft of openable window area and also reiterate the fact that a window professional should install a properly sized egress window. Puts the onus on the window company to install the correct egress window - and not any window some handyman says is an egress window. The previous sketch is a great reference to understand it.