I don't know what you mean by the "green" parts. If you mean the color green, the "skin" is stretched re-purposed medium weight canvas drop cloth, applied with ~7k 1/2" staples, then coated 3 times with a wet slurry of Reblended paint, water, and portland cement, before the final coat of just paint with boro-silicate microsphere insulation added with 2 more coats (by far the most expensive material in this whole project at ~$1/sq ft of coverage). IF, you are referring to "green" as in environmentally friendly, that comes from the majority of the paint, canvas, steel, and wood having come from free and salvaged sources. The two 14' trampoline frames took less than 2 weeks to find for free locally in Austin, but even new ones from Walmart are only $179 each, and is far superior than wood framing for the circular vertical walls. Eventually, I intend to set up a styro-foam re-pelletizer so I can embed more diverted "waste" products into the vertical walls as insulation.