We have no garage and a small yard. My husband made this using found things like the door and the window, and the foundation beam was washed up on our nearby beach. It holds bikes and gardening items like lawnmower etc.
Rubbermaid and other companies have heavy duty plastic type sheds also which may be cheaper -https://www.google.com/aclk?sa=l&ai=DChcSEwi2-o3Rp4jlAhVR1sAKHanyCAEYABALGgJpbQ&sig=AOD64_231ij-oSuXKBGK6m6gqmwQIFH6Sg&ctype=46&q=&ved=0ahUKEwjmg4bRp4jlAhUELqwKHZr7BUkQ9aACCFI&adurl=
We built ours out of free pallets. The walls are the height of the pallets standing on end, they are joined together and to the floor with nails, and the roof and cross beam are from tin. This is similar to but not exactly like what we built, but perhaps it can be a help: https://www.hometalk.com/2419337/making-a-pallet-barn