This new greenhouse (still in need of fully closing in) has a south wall (and return support walls) made of pallet assemblies. Each assembly is made from one and a half 4x stringer pallets with recycled polystyrene packaging for insulation and new polythene sheeting as an external cladding. The pallet interior is yet to have offcuts of Aircell foil backed bubble wrap fixed, as a light reflecting / waterproofing lining.
The rest of the materials are new and plastic covering was reused from my original greenhouse being UV resistant 'Solarweave' greenhouse plastic.
The whole building including prefab pallet assemblies took 1 person about 5 half days to build.