DESIGNERS
STEPS12345

1. DETERMINE PROJECT GOALS

  • If you haven't already, familiarize yourself with the basics of how the Silva Cell works. For any immediate questions, contact your local sales representative:

    For projects in the United States, email This e-mail address is being protected from spambots. You need JavaScript enabled to view it or call 415-781-9700.
    For projects in Canada, email This email address is being protected from spambots. You need JavaScript enabled to view it. or call 604-687-0899.
    For projects in the United Kingdom, email This email address is being protected from spambots. You need JavaScript enabled to view it.
    For projects in Europe, email This email address is being protected from spambots. You need JavaScript enabled to view it.
    For projects anywhere else in the world, email This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

  • Determine the target soil volume per tree using the "How Much Soil To Grow a Big Tree?" chart as a guide.
  • Determine how many trees on your site will need Silva Cells.
  • Will you be using the soil in the Cells to support trees only, or will you use it for stormwater treatment as well?

    If you want to use the Silva Cell for stormwater treatment, download the Stormwater Estimating Worksheet to estimate roughly how many Silva Cells will be needed to meet your treatment goal. Stormwater management always needs to be done within the requirements of governing agencies and using standard civil engineering practices. The specific design of the system should be refined with project modeling.

  • The Silva Cell is supported by the HydroCAD Stormwater Modeling System. (HydroCAD Stormwater Modeling provides easy TR-20, TR-55, SBUH, and Rational hydrology, plus TC calculations, pond storage, outlet hydraulics, pump routing, underground storage, pollutant loading, and more.)
  • Note that each Silva Cell frame can hold approximately 10 cubic feet (.28 cubic meters) of planting soil and 2 cubic feet (.056 cubic meters) of stormwater. Based on your project goals and the information provided above, estimate the number of Silva Cells that will be needed to meet your soil volume and, as applicable, your stormwater goals.

To maximize value, we recommend the following design guidelines

  1. Include the soil in the tree openings themselves as well the soil in adjacent open space accessible to the tree when calculating the total available soil volume in the area of work.
  2. Since each stack of Silva Cells needs one deck -- regardless of whether you are using the smallest post (1x), the mid-size post (2x), or the tallest post (3x) -- it is more economical to design a deep system than a wide system.
  3. Provide approximately 1,000 ft3 (28 m3) of soil for a canopy tree and 600 ft3 (17 m3) of soil for an understory tree. Stormwater treatment volumes will vary based on project location and goals.
  4. Always make tree openings as large as possible. This is the least expensive way to provide the tree with soil, and larger openings will accommodate the size and trunk flare as the tree matures.
  5. Wherever possible, use Silva Cells to link tree openings to each other or to existing nearby soil volumes, such as parks or lawns. Trees that share soil need less overall soil per tree than those in isolated soil volumes.

2. PLACE SILVA CELLS ON YOUR SITE
Now that you have estimated the number of Silva Cells you will need on your site to meet your project goals, you can begin to place them on your site plans. Or, for a small fee, we are happy to complete a Silva Cell layout for you. These and other design services may be helpful throughout the development of the project. Contact us at This e-mail address is being protected from spambots. You need JavaScript enabled to view it to find out more.

  • First, refer to the Silva Cell System Layout Instructions for a step by step tutorial on laying out Silva Cells on your project site plans.
  • After reading the Layout Instructions, we recommend that you refer to the AutoCAD video tutorial for a hands-on demonstration of the layout process.
  • We provide a Silva Cell "block" (look in the column on the right, under "Standard Details, Specifications, and Schematics" heading), which is available in different units, in AutoCAD format for ease of completing a Silva Cell layout and final material counts.
  • Read about the 5 most common mistakes made on layouts before beginning your own layout in order to save time.
  • To complete your drawing package, incorporate Silva Cell sections that reflect your design.
  • Standard and Modified Silva Cell sections are provided in AutoCad format. These sections can be used to illustrate standard Silva Cell component parts, dimensions, and pavement profiles.

3. CREATE A SILVA CELL SPECIFICATION
To complete project documentation, incorporate Silva Cell specifications.

  • We provide specifications for both the Silva Cell and our recommended soil mixes.
  • Soil is extremely important to the success of your trees and your stormwater management goals. Proper soil selection is a large topic that is way more complex than we have room to discuss here. We do offer tree and soil design services; please contact us at This e-mail address is being protected from spambots. You need JavaScript enabled to view it for further information or to receive a quote for this.

    To read more about soils, we recommend referring to James Urban's book, Up By Roots.

4. BUDGET PRICING
The Silva Cell has many possible configurations, and there are no one-size-fits-all pricing guidelines. Costs will vary based on characteristics of the site, the quantity of frames and decks required for the project, the tree size and stormwater treatment goals, and the design objectives. Remember that each frame is 48'' (1200 mm) long x 24'' (600 mm) wide x 16'' (400 mm) high and holds about 10 ft3 (.28 m3) of soil.

According to bid tabulations from projects across North America, the Silva Cell system generally costs $14 - $18 per cubic foot installed (that estimate includes everything except the base course, the final paving and the tree itself).

For cost efficiency, we recommend the following design guidelines:

  • Include the soil in the tree openings themselves as well the soil in adjacent open space accessible to the tree when calculating the total available soil volume in the area of work.
  • Decks and frames are priced differently, and frames are less expensive. Since each stack of Silva Cells needs one deck -- regardless of how many frames there are -- it is more economical to design a deep system than a wide system.
  • Provide approximately 1,000 ft3 (28 m3) of soil for a canopy tree and 600 ft3 (17 m3) of soil for an understory tree. Stormwater treatment volumes will vary based on project location and goals.
  • Always make tree openings as large as possible. This is the least expensive soil you can "buy," and larger openings will accommodate the size and trunk flare of a mature tree.
  • Wherever possible, use Silva Cells to link tree openings to each other or to existing nearby soil volumes, such as parks or lawns. Trees that share soil need less overall soil per tree than those in isolated soil volumes.

Contractors, please This e-mail address is being protected from spambots. You need JavaScript enabled to view it or call (415 781 9700) for an estimating worksheet.
For price information specific to your project, contact us (This e-mail address is being protected from spambots. You need JavaScript enabled to view it) for a quote; we'd be happy to assist you.

5. SUBMIT YOUR PLAN FOR REVIEW
Our goal is to grow long-living street trees. In order to help ensure the success of your project, we require plan reviews for all Silva Cell projects.

Submit your plan as early as possible, preferably at the schematic design stage, for the most flexibility. After reviewing the plans, we will send you written suggestions to make sure the Silva Cell system meets your project and budgetary needs.

How to send your files for review: Please send your drawings in the format that best fits your review needs. For a basic review of Silva Cell layouts and sections, PDF files work quite well. For a more detailed review, a formal Silva Cell layout, custom sections, or shop drawings, we recommend sending project information as eTransmitted CAD files.

Please contact your representative to start the plan review process, as well as for any questions about the parameters of your project, your goals, and pricing.

  • For projects in the United States, email This e-mail address is being protected from spambots. You need JavaScript enabled to view it or call 415-781-9700.
  • For projects in Canada, email This email address is being protected from spambots. You need JavaScript enabled to view it. or call 604-687-0899.
  • For projects in the United Kingdom, email This email address is being protected from spambots. You need JavaScript enabled to view it. or call
    +44 (0) 207 969 2739.
  • For projects in Europe, email This email address is being protected from spambots. You need JavaScript enabled to view it.
  • For projects anywhere else in the world, email This e-mail address is being protected from spambots. You need JavaScript enabled to view it or call 415-781-9700.