You could erect the 4 x 8 Sidemate Shed without a foundation, but using the foundation kit will give you the best long-term results. The kit is made of galvanized metals to protect against corrosion. One of the main benefits of using the foundation kit is that it will ensure that your shed is installed completely square. The foundation also elevates the floor of the shed off of the ground and protects it against ground moisture. The plywood floor is not included. The shed and foundation kits are sold separately. The foundation dimensions are 73" H x 48" W x 94" D.