This new shed is simple 2x4s, plywood, and tin roof. A 5'x5' footprint, it is small but very useable. It's small enough to be moveable, if needed. It is too heavy to move by hand, but a skid steer with forks can handle it with no problem (yes, I've already checked.)
At first I was going to make it 4'x4'. It seemed to be a more efficient use of the lumber. But when I thought about how I would be using the shed, I figured that 5'x5' would be more useable. Something larger would be too difficult to move to a new location, so 5'x5' was my final decision.
A small shed like this is simple to build. There are lots of easy to follow plans on the Internet. It took two days to finish it only because we took our time. I think it took about 10 hours to build from start to finish. But that doesn't include painting it or finishing off the inside, tasks I still need to do.
Since I had a small plastic tank that I wasn't using at the moment, I opted to create a rainwater catchment system off this shed roof. It won't be a lot of water, but it should be fine for washing off a few tools as needed. I haven't finished this set up yet. The gutter is in place but I still need to cobble together some pvc piping or hose to channel the water into the tank. Then I'll need to install a spigot in the bottom of the tank. Finishing it off with a deep sink or washtub below the spigot should be sufficient. I've got those in the boneyard and just have to decide which would be better to use here. I'll show you a photo when I have it completed.