Made me go to google on that one. For the benefit of those who might think fenestration is some sort of sinister Catholic ritual:
Would you let anyone fenestrate your building? You do when you let your architect put openings in it. Fenestrations are usually window openings and, if your architect uses this word, he is eager to impress you. Don’t be. Anyone can do it. Windows, doors, glass and glazing are all covered in this division.
But saying "I'm having new windows put in" sounds so pedestrian!
(Fun with vocab: Being "de-fenestrated" refers to being thrown out of a window.)
SD