5 Steps to Preserving Trees During Construction

Tree Resource Evaluation Map

There are many reasons to preserve during construction, including legal requirements, aesthetics, property value and ecological benefits. However, in order for a tree to be considered “preserved” it must survive construction and thrive for many years afterward. In order for trees to be preserved, there are five steps that should be followed:

1. Planning Phase
The planning phase takes before any site disturbance. Trees and the overall site are assessed so that construction and preservation decisions can be made. Accomplishments during this phase include:
Site survey showing all relevant features:

• Trees
• Hydrology
• Soils
• Utilities
• Existing structures

 
Tree Resource Evaluation

• Size
• Species
• Condition
• Suitability for conservation (Good, moderate, poor)
• Landmark/heritage trees
• Transplant?

​2. Project Design
During this phase, initial construction documents are developed, and a tree preservation plan is developed to consider trees based on construction plans. Specific steps during this phase include:

• Location, size, shape of buildings determined
• Evaluation of development impacts
• Drainage
• Grading
• Tree preservation plan developed

​Tree preservation plan components include:

• Areas to be preserved
• Tree protection zones, with barriers
• Soil erosion controls
• Staging and storage areas
• Signage
• Utilities

3. Pre-Construction
During this phase, the trees and site are prepared for actual construction activities. Accomplishments during this phase include:

• Protection specifications/goals communicated to all
• Protection zone barriers installed prior to work
• Tree removal operations shouldn’t damage trees to remain
• Root pruning, other treatments

 
4. Construction
The construction phase is where actual site disturbance and building construction occur. The construction phase is where physical tree impacts are most likely to happen. Accomplishments during this phase include:

• Arborist monitoring and reporting
• Corrective measures specified/implemented for any damage
• Periodic contractor meetings

The most common tree damage during construction includes:
-Root cutting/damage

• Excavation equipment
• Trenching equipment
• Burning/burial of debris
• Fill soil over roots and altered water tables
• Soil compaction

-Mechanical injury to trunk, major roots, crown
-Root collar covered by fill soil
 
5. Post-construction
This phase includes the time period after building construction and most site disturbance is complete. Steps to this phase include:

• Tree conservation recommendations revised if construction activity has altered tree health/maintenance needs
• Tree health monitored
• Long-term tree maintenance specifications implemented
• Preservation evaluation – Did it work? Can effects be mitigated?

 
As can be seen, there are many steps to preserving trees during construction. However, the effort is worth it to preserve trees that bring significant benefits to a property. In order for trees to be properly preserved, an arborist must be brought in to a project in the project planning phase. If trees aren’t considered until later phases of construction, it will likely be too late to properly protect them and allow trees to survive and thrive.
 

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