Roll-up side walls are offered as a component of Hortitech greenhouse kits. They are used for natural greenhouse ventilation. The plastic size for roll-up sides is the same that you would use for the greenhouse without them, but instead of securing the plastic with channels and wiggle wire, the side plastic is made into a roll-up side curtain using purlin and side handles.

You will need:
2 x roll up side handles 5' (one for each side)
20.25' purlin, to meet the greenhouse length (there will be some extra length)