Exclusive right to park on common property

Our building has 4 owners, in a building of 16, who do not have parking spots as part of their title.  They have asked the EC to give them the right to permanently park on common property.  They do not want to pay any extra levies or fee for this right and they want the rights if granted to pass to any future purchasers of their units.  Is this a reasonable request when other owners have paid a premium on the purchase of their unit with car parking, and can the EC give them this right without a Special Resolution going to an GM or AGM?