A tree risk assessment is a systematic evaluation of the likelihood that a tree or tree part will fail and cause harm to people or property. At Sylva Environmental, our ISA Certified Arborists and TRAQ (Tree Risk Assessment Qualification) holders conduct thorough assessments following the International Society of Arboriculture Best Management Practices (ISA BMP) for tree risk assessment. Whether you are a homeowner concerned about a mature tree, a developer preparing a site, or a municipality managing public trees, our reports provide the clarity and documentation you need to make informed decisions.
What Is a Tree Risk Assessment?
A tree risk assessment is a detailed inspection conducted by a qualified arborist to evaluate the structural condition and health of a tree in relation to its surrounding environment. The assessment considers the likelihood of tree failure, the potential targets (people, structures, vehicles, utilities), and the consequences of impact. The goal is not simply to determine whether a tree is "safe" or "unsafe." Instead, it assigns a risk rating that helps property owners and managers prioritize action, allocate budgets, and satisfy regulatory or insurance requirements.
Unlike a general tree health check, a risk assessment follows a standardized methodology defined by the ISA. This ensures consistency, defensibility, and professional accountability. Reports produced under these standards are recognized by municipalities, insurance companies, and courts across British Columbia.
ISA BMP Methodology and TRAQ Qualification
The ISA Best Management Practices for Tree Risk Assessment represent the industry standard for evaluating tree risk in North America. The methodology uses a matrix that combines the likelihood of failure, the likelihood of impacting a target, and the consequences of that impact to produce a final risk rating. These ratings range from low to extreme and provide actionable guidance for tree owners.
Our arborists hold the Tree Risk Assessment Qualification (TRAQ), which is a specialized credential issued by the ISA. TRAQ holders have completed advanced training in biomechanics, failure patterns, wood decay, root assessment, and environmental factors that influence tree stability. This qualification is renewed through continuing education and ensures that our assessments reflect current science and best practices.
Level 1: Limited Visual Assessment
A Level 1 assessment is a walk-through survey designed to identify obvious defects across a large population of trees. This assessment is typically used for parks, campgrounds, road corridors, and large commercial properties where hundreds or thousands of trees need screening. The arborist walks through the site at a normal pace, looking for clearly visible signs of failure potential such as dead trees, large hanging branches, severe trunk cracks, and root plate lifting. Trees that present obvious concerns are flagged for closer inspection at Level 2.
Level 2: Basic Assessment
A Level 2 assessment is a detailed, individual tree inspection conducted from the ground. This is the most common type of tree risk assessment and involves a 360-degree visual examination of the tree's crown, trunk, root flare, and surrounding site conditions. The arborist evaluates structural defects including cracks, cavities, decay, co-dominant stems, included bark, root damage, lean, and canopy dieback. Environmental factors such as soil conditions, drainage, exposure to wind, and proximity to targets are also documented. The assessment produces a written report with risk ratings, photographs, and management recommendations.
Level 3: Advanced Assessment
When a Level 2 assessment identifies a defect that requires further investigation, a Level 3 advanced assessment uses specialized diagnostic tools to gather additional data. This may include resistograph drilling to measure internal decay, sonic tomography to map wood density, root collar excavation using an Airspade, or laboratory analysis of wood samples. Level 3 assessments provide the highest level of detail and are typically used for high-value trees, trees adjacent to critical targets, or situations where the Level 2 findings are inconclusive.
When You Need a Tree Risk Assessment
There are several common situations where a tree risk assessment is necessary or strongly recommended.
- Development permit applications. Most municipalities in BC require a tree risk assessment or arborist report as part of the development permit process. The report documents existing trees on the site, assesses their condition, and provides recommendations for retention, removal, or protection during construction.
- Insurance claims and liability protection. If a tree fails and causes damage to neighbouring property, a pre-existing risk assessment demonstrates due diligence on the part of the tree owner. Insurance companies increasingly request tree assessments as part of property evaluations, particularly for properties with large, mature trees.
- Municipal compliance. Many BC municipalities have tree protection bylaws that require property owners to obtain an arborist assessment before removing or significantly altering trees above a specified diameter. A risk assessment satisfies this requirement and provides the documentation needed for permit applications.
- Post-storm evaluation. After a significant weather event, trees may have sustained hidden damage that is not immediately apparent. A risk assessment identifies compromised trees before they fail during subsequent storms.
- Real estate transactions. Buyers and sellers benefit from knowing the condition of trees on a property. A risk assessment can identify potential liabilities and inform negotiations.
- Neighbour disputes. When a tree on one property poses a potential risk to an adjacent property, a professional risk assessment provides an objective, standardized evaluation that can help resolve disagreements.
What the Report Includes
Every tree risk assessment report from Sylva Environmental includes the following components. A site description with mapping of assessed trees. Individual tree data including species, size (DBH), height, crown spread, and condition ratings. Photographic documentation of all significant defects and site conditions. Risk ratings assigned using the ISA matrix methodology. Specific management recommendations for each tree, which may include monitoring, pruning, cabling, bracing, or removal. A summary of findings and prioritized action items. The arborist's credentials, signature, and TRAQ number.
Reports are delivered in PDF format and are formatted to meet the submission requirements of municipalities in the Kelowna, West Kelowna, and Greater Vancouver areas. We can also provide supplementary materials such as tree protection zone plans and construction impact assessments when required.
Our Assessment Process
The process begins with a consultation to understand your objectives, whether that is a single tree concern, a development application, or a full property inventory. We schedule the field assessment at a time that allows for thorough inspection. Weather conditions may influence scheduling, as certain defects are more visible during specific seasons or conditions.
During the field visit, the arborist conducts a systematic inspection using the appropriate assessment level. All data is recorded digitally, and photographs are taken to document findings. If advanced tools are needed (resistograph, Airspade, or tomography), these are either included in the initial visit or scheduled as a follow-up depending on the scope.
Reports are typically delivered within five to ten business days following the field assessment. Rush turnaround is available for urgent situations, development deadlines, and emergency assessments. We are always available to discuss our findings with you, your contractor, your insurance provider, or municipal staff.
Service Areas
We provide tree risk assessments throughout British Columbia, with primary service areas in Kelowna, West Kelowna, Peachland, Lake Country, Vernon, and the Central Okanagan. We also serve Vancouver, North Vancouver, West Vancouver, Burnaby, Surrey, and the broader Lower Mainland and Sea-to-Sky corridor. For larger projects outside these areas, contact us to discuss availability and scheduling.