Sentence:  We are rather stifled by the Administration, however, until the second and third floors of the <WSD>backwings</WSD> are completed and we can kick the Applied Mechanics Department and Mineral Industries Department out, when they can move in the new Academic Science Building when that is completed, at which time then we will have space for a lounge. 
Meaning of the word marked with <WSD> tags:  A wing at the rear of a building.