While a window may present itself as the initial point of your fire attack, it does not allow for your nozzle team to make the quick entry needed in order to extinguish the fire. (Mark Brady, PGFEMS photo)
When it comes to fire attack many are looking to utilizing a window to apply their stream, this exterior attack is the first half of what is referred to as transitional fire attack. When a stream is operated from outside the structure through a window or door it is restricted.
You want to reduce the amount of restricted stream access to improve stream coverage and nozzle reach and gain extinguishment. If you conduct an exterior attack through a window you will typically acquire a knock back of the fire condition. Without the ability to instantaneously reposition that stream to the interior for extinguishment the fire will regrow.
The issue with window fire attack is that you may not be able to reposition your exterior stream for additional fire attack into the space due to the windows height or access issues. This issue becomes more prominent when the window is not at ground level.
Due to how your stream reacts to indirect fire attack there will be locations within the fire room that cannot be extinguished from outside through the window. This is why transitional attack relies on a second phase, you must move to an interior attack to gain extinguishment. Unrestricted nozzle movement is easily obtained once you're inside the fire room.
Doors also restrict stream access and gaining extinguishment. When a fire meets you at the entry door you must first attack it from a distance. That distance (outside the space) presents us with only the doors opening height and width which restricts your stream access and movement. I always teach that you should move past that restriction so that your stream placement is no longer restricted and you are out of the flowpath of any exiting heat and smoke.
Where windows and doors differ is that windows typically remain a physical barrier to entry while doors do not. Another factor is doors that you will apply your stream through are typically on the same level as you and provide a larger opening in which to deploy your stream. Doorways allows for rapid advancement while windows negate advancement.
Doors are a temporary restriction to your stream and advancement while a window restricts both access and advancement. Once you hit the fire room from outside the doorway enter the room and you will have full access for extinguishment, try doing that with a window.
Keep Fire in Your Life