All the technology in this building and the elevator breaks down (Bendytimed before Evil!Reed stuff)
 While normally he took the empty elevator shaft left over from the original F4 and human torch days to move between floors, Aleron did occasionally take the elevator. Mostly out of interest more than anything. It was more efficient just to step into the empty shaft and adjust his gravity to send him to the appropriate floor but...he kind of liked trying the more normal stuff.

So he waits in front of the elevator doors for it to come.