The area above the wash house was used to store and process grain, there was grinding machines and other equipment. The grain would have been used to feed the horses and also possibly used to make bread over at the mansion house.
Access to this area was through a small hatch in the floor above what is now the toilet shed and the main entrance was through the large door above the wash house itself. There was a set of wooden steps that made its way up there but when the area was no longer used the stairs were removed making the only access via the small hatch way in the floor.
What it looked like when in use, however no date is given