Private terrace

My C&S project has a terrace on the 1st floor (below there is only the parking garage). That terrace is only accessible by the Meeting Room, which is used by the building users. The meeting room is only accessible by the people that rent the meeting room (by hour). The terrace of that meeting room has native and adapted vegetation. Question: Can I count that area for SSc5.1, or is there any restriction to that area, as it is not completely acessible by everyone and is not considered roof above a densely occupied space? Thank you in advance!