Tree Risk Assessments

Tree risk assessments evaluate the condition of trees and their potential to cause harm to people, structures, or site improvements. For land development and redevelopment projects, these assessments provide a defensible basis for planning decisions, permitting, and risk management.

Assessments are performed by an ISA Certified Arborist and focus on observable conditions at the time of evaluation. The objective is to identify relevant defects, assess exposure to targets, and document professional opinions in a clear, structured format suitable for project use.

Purpose of a Tree Risk Assessment

Tree risk assessments are commonly required or relied upon when:

  • Planning site development or redevelopment

  • Evaluating trees near buildings, roads, utilities, or work areas

  • Responding to municipal or agency concerns

  • Supporting arborist letters and professional reports

  • Determining whether mitigation, monitoring, or removal should be considered

They are often used as a decision-support tool rather than a directive, allowing property owners and project teams to evaluate options based on documented conditions.

What Is Evaluated

A tree risk assessment may include evaluation of:

  • Overall tree condition and vigor

  • Structural characteristics and observable defects

  • Trunk, branch, and root-related concerns

  • Site conditions influencing stability

  • Proximity and exposure of potential targets

The depth of evaluation is scaled to the project context. Large development sites, construction corridors, and single-tree evaluations are approached differently, but the assessment framework remains consistent.

Professional Judgment and Scope

Tree risk assessments represent the certified arborist’s professional opinion based on visible conditions and accessible areas at the time of inspection. Trees are living systems, and conditions may change due to weather events, construction activity, soil disturbance, or lack of maintenance.

Assessments do not guarantee future performance or eliminate all risk. They are intended to inform planning and management decisions using accepted arboricultural principles.

How Risk Assessments Are Used in Development

In a land development context, tree risk assessments may be used to:

  • Inform site layout and design decisions

  • Support permitting and review processes

  • Establish baseline conditions prior to construction

  • Identify trees requiring monitoring during site activity

  • Support written arborist documentation and reports

They often work in coordination with tree surveys, protection plans, monitoring plans, and preservation strategies.

Deliverables

Deliverables are prepared in a professional format appropriate for coordination with project stakeholders, reviewers, and records. The scope and level of detail are aligned with the needs of the project rather than a one-size-fits-all template.

If your project requires clear documentation of tree-related risk to support planning or decision-making, a professional tree risk assessment provides the appropriate starting point.