I created this challenge for KS1 children as a way of assessing who understood different material qualities. it came at the end of a unit of work on space and materials. It was designed so the children could apply their learning of opaque/transparent/translucent, waterproof, warm and heavy, It also combined to cover some DT with ways of joining things. The children love this activity and really make this their own. I can think of many ways to extend this to older year groups including planning how to test it, testing different materials for best choice etc. Have fun.