Storage sheds can be professionally installed as well as self assembled. Usually for easy assembly, the parts are numbered in self-assembly type storage shed kits. Garden Storage Sheds are small buildings used to store garden implements, lawn mowers, and bicycles. Storage sheds should be no larger than 8 feet wide, 12 feet long, and 7 feet high at the peak of the gable and neatly painted. If sheds are built, they will need to be painted white or the color of the outside of your house.