There are three factors that should influence how big your bike shed should be. The first one is the size of the bikes that you want to store. If you have a large adult bike, you will need a big enough enclosure to fit it in when it is upright. Children’s bikes take up less room but remember that kids grow very quickly and soon need bigger bikes! Remember, that you need enough height. The second factor is how many bikes you want to store. Obviously, the more bikes you have, the bigger storage you will need.
Finally, you must take into account the amount of space that you have in your yard or garden. Bike storage can take up a lot of room and you may want to use your outdoor space for other things!