This is a great idea for children who want to play in the backyard and have a kind of shelter to make it more fun, and it's very beneficial because:

• They learn to protect the environment and recycle.
• They have fun, and are busy doing something productive.
• They will have a shelter which can be considered like their own castle in case of boys and a barbie house in case of girls. (Or a simple playing shelter for both)

If I had children, I would definitely build one for them, great idea :)!