Cristina, it is funny that you mention that because this summer, we actually did get a shed, and he (my son) helped out building it.
The Shigloo he built was just something fun: he wanted to build an igloo big enough to go in with friends, but making ice blocks was challenging so he figured that he could make blocks of ice by stuffing boxes with snow and piling them up. The result was… well… just like you see in the picture! What harm was there in letting him “work” on this project, even though it could never end up being something functional. He had fun. He was busy and getting in trouble otherwise. And a fun topic for a scrap page!