Because the shed is designed to abut to another structure, the foundation need only be pressure-treated skids, the roof pitched in only one direction to shed water, and the back wall sheathed with 1/2-inch CDX plywood, which withstands indirect exposure to moisture. See Anatomy of an Outdoor Shed or Playhouse for more about typical shed construction.
Normally we try to help our customers as much as possible, especially if it is a matter of helping to figure out where certain material goes on the building. Keep in mind, you are responsible for correctly constructing the shed if you purchase a kit, but we can offer direction. (Prior construction experience is recommended.) If there is any uncertainty about whether or not you will be able to assemble the storage shed, consider one of our build-on-site options and we will send a team to assemble the building for you.
The best spot for a shed is level, well-drained ground close to where you work in your garden or yard. The location doesn’t need to be perfectly flat; the foundation design shown in the plans allows for adjustments to make the floor level. Small sheds require only a top-of-soil foundation, even in locations with freezing winter temperatures. Precast concrete deck blocks work perfectly for this.