Foundation For Building Size(s) 12×12 Quick Assemble Standard Shed Base. Establish a foundation for a garden construction utilizing an EcoBase Quick Assemble Base Kit. Serving as an eco-conscious substitute for paving slabs or fluid-mix concrete, Ecobase Fastfit consists of reused networks that link together to grant you a solid, sturdy, enduring, and properly-drained base for your garden structure. Foundation For Constructing Size(s) 12×12 Quick Assemble Standard Shed Base