Bedroom window | Egress – Light – Ventilation

Bedroom windows are a way to get out of your home in case of an emergency. They need to be big enough to fit a human and open clear enough to give an access to a fireman.

If you have been in a compromising position where you must exit quickly, you will realize how crucial bedroom egress windows are.

You should have windows that let in light, provide ventilation, and have an egress if you want to increase your home’s value and maximize its livability.

Egress Window Calculator

Enter your clear window opening dimension below to see if your bedroom window meets egress requirements.

Window Egress Calculator

(The minimum clear width is 20 inches) inch

(The minimum clear height is 24 inches) inch

All the inputs are required.

Window opening Area


Bedroom Egress Window

If you install any additional bedrooms in your beloved home, you must have egress windows installed in your sleep areas for lots of reasons:

  1. To allow an escape route in case of emergency.
  2. The window in the basement makes the space habitable. 
  3. Your home will be more valuable.

Measurement of Egress Window

International Residential Code, bedroom windows should have these requirements. (IRC 310.1),

  • The open window should be at least 24 inches in height. 
  • A minimum clear width of 20 inches.
  • A net clear opening of at least 5 square feet of glass area is required for grade floor windows or below grade only.
  • A net clear opening of at least 5.7 square feet of glass area is required for stories above grade level. 
  • A sill is no higher than 44 inches off the interior floor. 
  • When the window is above 44 inches from the interior floor, the ladder should be permanently attached. 
  • At a minimum, the ladder must be 12 inches wide and no less than three inches from the window well, which should not encroach more than six inches on the required open window. 
  • If a window is located under a porch or decking, it must be at least 36 inches below the floor joists. 
bedroom egress window requirements

Calculating Egress window area

To measure the window area, use the formula its (width with its height).

Use this simple formula to determine if your window area is more significant than or smaller than a good Egress window area.

You need to measure the clear opening width and height of the bedroom window. Measure tapes are in inches, the total area should be divide by 144.

For example, if the clear width is 25” inches and the height is 35” inches. The clear area (25 x 35) = 875 square inches.

The net clear area is 875 / 144 = 6.07 square feet. which is greater than 5.7 sq. ft. This bedroom window meets the minimum building code requirements.

Read more: Basement Egress window code requirements.

How to Achieve Perfect Egress Bedroom

  • We are increasing the window size instead of width. The horizontal structural header might be a good option. 
  • Increase the height, width of the window to the new standard. 
  • You can lower the window to no more extended rest on the sill.

Note: There are some situations where you replace your windows to meet the requirements for egress windows.

An Egress window is necessary for any residential building and must meet standard size. It’s designed to get you out of a home in an emergency.

Bedrooms or basements that must have windows that can open to provide an egress require escape routes.

Remember, it should be capable of opening without any knowledge, unique skill, special software, or hardware.

Ventilation and Lighting 

While artificial lighting and mechanical ventilation are possible to meet the needs of a bedroom, the room will certainly become a disheartening environment rather than a pleasant retreat from the world.

Instead, comply with the codes. There should be at least one window in the bedroom, and the total glass area of all windows should be at least 8% of the floor area for the minimum natural lighting and 4% of the floor area for the minimum ventilation.

An example of this would be if you have a 200 square feet bedroom area,

The required lighting for this area is 8% of the total bedroom floor area. The total lighting area = (200 x 8)/100 = 16 square feet

The required bedroom ventilation = (200 x 4)/100 = 8 square ft.