I was around the industrial state yesterday and noticed the conservatory builders putting all their triple glaze plastic offcuts in the skip. Can I have a few bits I asked, take what you want we have to pay to tip it.
Now this stuff can be cut easily for cold frame tops, a homemade greenhouse, shed windows etc. It needs to be stapled to timber as it is light and will blow away in the wind but pallet wood should do.
So if you want a free coldframe etc. Get around to your local conservatory builders.