It might not be for scooby, but i dont think there is as much space as thought up the back. There are water tanks and some plant building permanently in that space as it is.The fencing put up for previous fright nights that follows the access road is still there too.
That means the whole "hill" behind scooby is fenced off right to the access road behind the show stage. I imagine if you drew a line from the top of this road across show stage, that would form the building site for scooby. No chance of anyone going into a build site without a white card, so you might as well say its a complete exclusion zone to everyone, even staff.
The gravel area in front of the sheds was used for queue lines for the mazes last fright nights. The road was permanently fenced on both sides and you walked up from the arkham courtyard to the gravel area, so i imagine itll see similar use this year.