Each Silva Cell is composed of a frame and a deck. Frames are 48'' (1200 mm) long x 24'' (600 mm) wide x 16'' (400 mm) high, and each one holds 10 cubic feet (.28 cubic meters) of soil. They can be stacked one, two, or three high before they are topped with a deck to create a maximum containment area for lightly compacted loam soil. Silva Cells can be spread laterally as wide as necessary. Each unit is about 92% void space, making it easy to accommodate utilities.
Six rigid vertical posts protrude from the bottom of the frame to support hardscape along with the weight of any load they carry. Their rounded edged prevent significant stress concentrations, meaning that the supported hardscapes are in no danger of sinking due to compressive forces.
The deck is a rigid platform with six recesses position to snap securely on the six posts of the frame. Openings on the deck allow ample room for air and water to penetrate to the enclosed soil.