The shed idea is not really a good one for security reasons. If just one of the neighbourhood kids find out about it you will have all sorts of problems and worries. The least of which are the cops showing up at your house because a neighbour reported a prowler in your backyard. They will try to rip off your grow.

I don't know your situation as far as teens go, like do you have any, are there any living in your area? but if you can't make it totally secure then I would forget about the shed and just grow in your house.