Venting a clothes dryer through a window

My friends purchased a co-op w/an existing Maytag Neptune washer/dryer. The dryer is venting through a window. But now that they are undergoing a renovation, the co-op wants the dryer to be vented through the brickwork. There is nothing in the Alteration Agreement or Proprietary Lease that governs proper dryer ventilation. Can my friends claim that they should be grandfathered-in -- and allowed to continue to vent through the window? I've read the Dept of Bldg's Plumbing Codes "504.1", "504.6" and "504.6.1." (Are you still awake?) These all pertain to venting dryers through brickwork. (And no, they don't have a ductless electric dryer.) I can't find anything about the legality of venting through a window.

Thanks to all for any help or advice.