i-Tree Design and Planting FAQs

Which tool should I use for my tree planting project?

Both i-Tree Design and i-Tree Planting provide useful outputs for planning a tree planting project, but the answer will depend on how many trees you hope to plant. For a smaller project (less than 25 trees), i-Tree Design will provide great reports and visuals but for larger projects, i-Tree Planting will be a better suited tool.

What if my trees are shorter than DBH (4.5 feet or 1.37 meters) at the time of planting? What should my DBH input be?

The minimum DBH input accepted by i-Tree is 1 inch (2.54 cm). One approach to this problem is to adjust projection time length from your estimate of when trees will reach minimum DBH. For example, if your tree takes 3 years to reach 1 inch DBH, change your projection length from 20 to 17 years.

Why am I getting negative energy savings values for my tree?

A tree can have a negative energy impact on energy costs when it blocks winter sun leading to increased need for heating the home than if the tree were not in that location. Furthermore, energy costs for winter heating can be greater than electricity costs for air conditioning in the summer. As such, winter negative effects can offset summer cooling benefits in same case resulting in an overall negative effect.

What tree mortality rate should I use for my i-Tree Planting project?

The default annual mortality rate is 3% or 70% over project lifetime of 40 years based on previous studies of survival of urban trees. If you have more localized tree survival rates, you can use those values for your project.