I demolished a barely used rotten shed and realized that it had a nice concrete pad under it. It was facing South so I decided to put a simple obsy on it just for that part of the sky - because that's all the space I've got besides the driveway where I normally set up.
The design is as simple and as cheap as it gets. It is a 6x8' metal shed modified to make the roof a lid that I can slide off and on with 2 handles, no rails. The shed was $490 after taxes, the handles $30, built with some plywood and 2x2s cut from 2x4s from the old shed.
Here's how it works, I'm pretty happy with it. We have grey and wet weather so I didn't set up my gear in it yet. I have yet to seal the cracks under the wall that let water in.