How Many Feet Must a Window Be Above Ground to Have a Bedroom in the Basement?

Habitable Space

• Once a bedroom is added to the basement, it becomes habitable space, triggering additional construction requirements. Most local building codes use the International Residential Code as a model for their own regulations.The codes are prepared to ensure the health and safety of occupants and call for measures that improve the quality of the living space. Mandatory egress in every bedroom in the event of an emergency is the most important regulation that affects basement windows.

Egress Window Dimensions

• Windows don't have to be above ground to allow a bedroom in the basement, but when they serve as emergency egress, they need to conform to the dimensions laid out in building codes. The sill height of the window on the interior side must not be more than 44 inches above the floor and not more than 44 inches above or below the grade level of the finished ground level adjacent to the window.

Height of Basement Window

• While the basement window for a bedroom doesn't have to be above ground, there are rules for the minimum height and width of the window. The minimum opening height is 24 inches, and the minimum opening width is 20 inches. If the window is sized to both the horizontal and vertical minimum dimensions, it won't meet the required net clear opening of 5 feet for basement windows. The minimum height or width has to be extended.

Window Well Dimensions

• Window wells protect the window material from moisture penetration and allow more light into the basement. They have to be constructed to a size that permits egress through the window. The clear horizontal dimension must allow the window to be fully opened. Net clear opening for the window well is 9 square feet, and the minimum horizontal projection and width is 36 inches. When window wells are deeper than 44 inches, a permanently fixed ladder or stairs must be installed.