You don't think there would be more than one floor/window in the building that the fireman might need to access? Particularly since they would not know in advance which floor the fire was on etc.
Picture his.....The Firemen arrive with their ladder truck....Smoke is billowing out of the upper floor windows of the TSBD.....but there are seven red rings on the windows ..... Where do they place their ladder?? If they placed a ladder at the east end of the sixth floor where there was a red ring......Nobody inside would have access to that window, because it was blocked by boxes of books.