Exceedingly simple to build this kind of cladding: just press shells into wet lime mortar. Even collecting enough shells is simple if you have a friendly seafood restaurant nearby. For bonus points you can even make the mortar out of the very same scallops to begin with. Using natural materials is inherently Green.

https://hell.twtr.plus/media/a2a1a956fd710ebc7062a1aae3c0ae49c4c84a8c4e2a8a7cb6ae3f4943f24c8b.file
https://hell.twtr.plus/media/65a6628fec1682022b153e6395f9d9409ea36c005ac19541e9a7536f50d2bc4b.file
https://hell.twtr.plus/media/08502fc7a01bc3d14cc0655f6b7803fb7c101edf33d666f464d073a47418ced3.file
https://hell.twtr.plus/media/d76514cfa811b176fb9e9b982425c10423a09fcbb3bbbbb8e6fa8c6052d7c5b4.file