I'm only a driver not a performance specialist, but taking an average from our regular destinations, 7500 ft seems to be about the minimum you'd need assuming ISA SL, a dry runway and no obstacles to get an 89 tonne aeroplane airborne. It would almost certainly require a config 3 departure.We use balanced field calculations which is more restricting and I have no idea whether this is an industry-wide policy.
Hope this relatively vague answer might be of some help, but the A320/321 performance is very complex and usually makes extensive use of improved climb techniques.