Properly sized egress windows are an important design consideration for any home renovation project or the construction of a new home. If your home is relatively new, the egress windows more than likely already meet the design criteria. However, if you are remodeling an older home, chances are the original windows are smaller than the current code requirements. You should take this opportunity to install new, larger windows that meet the new standards. In this article, we will look at the dimensional requirements.
The Need for Egress Windows
Before we dive into the dimensional requirements lets first take a look at why you need egress windows in the first place. The obvious answer is that in the event of a fire in your home you need a way out. This is particularly true if you are situated in a bedroom or perhaps your basement when a fire breaks out. The stairway or hallway may be blocked by intense heat and flames or simply filled with thick black smoke making it difficult if not impossible to pass. In this situation, you need a secondary means of egress to escape from your home quickly and safely.
These same windows, may also be utilized as an entry point for fire fighters whom enter a home to rescue the residents trapped inside. In this case, the dimensions of the windows may be even more critical to allow ample space for a Firefighter with full gear, easy entry into your home.
Dimensional Requirements for Egress Windows
According to the International Building Code all bedrooms and basements that are situated below the 4th floor of a structure must have a minimum of one exterior escape access. This could be conventional window or a patio door but it must meet specific dimensional criteria to qualify as a true means of egress.
Clear Opening: The minimum clear opening of the egress window must encompass a total of 5.7 square feet. Keep in mind, that this is the actual net opening with no obstructions. Meaning the net opening inside any trim or stops. Ground floor windows can be slightly smaller at 5 square feet since there is no need to insert a rescue ladder which would otherwise infringe upon the overall opening.
Width & Height: The window must have a minimum clear opening of 20 inches wide and 24 inches high in the full open position. Of course, at least one of these dimensions must be greater than the minimum to achieve the 5.7 square foot threshold.
Window Sill Height: The maximum height of the window sill for an egress window is 44 inches from the floor. This is to ensure that residents can reach and climb out the window without the need of a stool or ladder on the inside.
Interior Operation: Egress windows must be fully functional from the inside of the home without the need for any tools or keys. This also means that the windows cannot be covered by security bars or grills.
Basement windows present us with additional challenges. If your windows happen to open into a window well there are a few additional considerations as follows:
Clear Access: Basement windows, such as a casement window, must be able to fully open into the window well.
Fixed Ladders: If the window well is deeper than 44 inches it must feature a fixed ladder for easy exit. The ladder itself must be at least 12 inches wide and the ladder rungs must be at least 3 inches deep. In lieu of a conventional ladder, the means of egress could be steps constructed of block or landscape timbers.
Deck Clearance: If your basement window happens to be located under a deck, the underside of the deck must feature a minimum clearance of 36 inches.
So, as you can see there is much more to your fire safety plan than checking the batteries on your smoke detectors every 6 months. Speaking of which, we just changed our clocks for daylight savings time. Did you remember to change your batteries?