For nearly maintenance-free storage units, vinyl is the preferred siding. Vinyl lacks the visual appeal of wood, but if you own a house with vinyl siding, why not select a storage unit that is also sided with vinyl? However, vinyl will get dirty over time, making it even less attractive. Mold is often the culprit. Take into account the maintenance required to clean the vinyl periodically.
Do-It-Yourself Outdoor Storage Buildings vs. Professional Installation - If you'd prefer that most of the work be done for you, then just select a shed from your local home improvement store and ask that it be delivered and assembled by the pros. But those who are handy may wish to save some money and order an outdoor storage building kit that comes with assembly instructions.