Project Overview

One of four projects to build inviting, eco-friendly parks in Downtown Dallas, Pacific Plaza transformed in 2018-19 from a concrete parking lot to a 3.7-acre urban green space. The original plan was for the 36 trees to be planted in structural soil; however, the construction team at The Beck Group — having worked with DeepRoot in the past — recommended Silva Cells instead. The result was less site disturbance and a lower cost and soil compaction, resulting in healthier, better-performing trees within an AIA- and ASLA-award-winning urban plaza.

Silva Cells: A Cost-Efficient Alternative to Structural Soil

In the original plans, SWA called for the 36 trees to be planted in a gravel-based structural soil under the pathways leading into the heart of the park, thinking that soil cells were too expensive for the budget. The Beck Group, whose construction division had previously completed successful projects using DeepRoot Silva Cells, recognized the advantages of loam soil for tree growth (as opposed to the rock mix) and proposed substituting the Silva Cells for the structural soil. They also pointed out that the tree would have a soil volume increase for less money because of the 93% or more void space in the cells (versus the 80% rock in the gravel-based structural soil mix).

After DeepRoot’s experienced technical team provided detailed sections and plans as shop drawings to SWA Group, they readily agreed to the change in order to provide the best possible growing environment for the promenade trees, and at a reduced cost to them. Indeed, studies from the Urban Horticultural Institute at Cornell University note that the substitution would be a net increase in soil volume for the trees.

Silva Cells Success

“At the Beck Group, we understand that by using DeepRoot Silva Cells we can remove a large quantity of structural soil and replace it with a smaller quantity of Silva Cells and achieve the same structural requirements above ground, and have much healthier, better-performing trees,” observed Jim Shipley of The Beck Group.

Likewise, the electrical conduit and drainage pipes were easily accommodated due to the open space within the Silva Cell units and the ability to provide space between the units. The flexibility, modularity, and ease of construction of the Silva Cells were evident throughout the installation — and the excavation and hall-off quantities of soil were significantly reduced by switching from the proposed structural soil solution.

Jim Shipley ultimately praised the Silva Cells for the creation of a flourishing green oasis in Downtown Dallas: “By using DeepRoot Silva Cells at Pacific Plaza, we were able to install a much smaller quantity of material, which meant we had to excavate and haul off less soil. For our customer, Parks for Downtown Dallas, they were able to deliver a green space within walking distance to businesses and downtown residents on budget.”

Project Awards

-2020 Texas ASLA Honor Award

-2020 AIA Dallas Built Design Award