Short range is 8 meters. It is about 0.8 "tiles" in NWN2, viewable from the toolset or if you guess in game. Interior tiles are slightly smaller, so it is about 1 tile or so inside.
8 meters in feet is around 26 feet.
3.5E notes Edit
Short range, called Close in 3.5E is defined as:
Close: The spell reaches as far as 25 feet away from you. The maximum range increases by 5 feet for every two full caster levels.
Because of NWN(2)'s CRPG sizes, that is the area's buildings and distances are not to any real life scale, this doesn't fit, and would be unbalancing. The maximum range at level 20 is still a good 75 feet, which is longer than NWN2's Medium range.