The important thing to understand up front is that not all arborist reports carry the same weight. The qualification of the person who signed it determines whether a council will accept it, and reports from under-qualified arborists are routinely knocked back.
What is actually in an arborist report?
The contents vary with the purpose, but a report prepared for a council decision generally covers:
- Botanical and common name of each tree, its location on a site plan, and a unique reference number for each tree.
- Height, canopy spread and trunk diameter, usually measured at a standard height above ground.
- Health and vigour. Condition of the canopy, foliage density, evidence of dieback, pest activity or disease.
- Trunk and branch architecture, included bark, cavities, decay, root plate condition, previous poor pruning.
- Useful life expectancy. How much longer the tree can reasonably be retained in that location.
- Landscape significance. What the tree contributes to amenity, canopy and habitat, which is what councils weigh against your reasons for removal.
- Retain, retain with pruning, monitor, or remove, with the reasoning stated.
- Supporting material. Photographs, a site plan, and where relevant the results of any testing.
Where the report supports development, it will also include an arboricultural impact assessment and a tree protection plan. Those are the parts that determine whether your build can proceed as designed.
What are the different types of arborist report?
“Arborist report” is used loosely to cover several distinct documents. Councils and certifiers usually know which one they want, and asking them before you commission anything avoids paying for the wrong report.
Tree condition or tree health report. An assessment of a single tree or a group of trees: species, health, structure, useful life expectancy and recommended action. This is the report behind most standalone removal or pruning applications.
Tree risk assessment. Focused specifically on the likelihood of failure and the consequences of it, taking into account what sits beneath the tree. Recognised risk assessment methodologies exist and are the basis for defensible risk work, which matters where an insurer, a strata committee or a court may later examine the decision.
Arboricultural impact assessment. Prepared for development. It maps the trees on and adjoining the site, calculates their protection zones, assesses what each element of the proposed works does to each tree, and rates the impact. This is the document a consent authority reads to decide whether your design is acceptable.
Tree protection plan. The companion document to the impact assessment. It specifies the physical protection measures, fencing, ground protection, supervision requirements and stage-by-stage controls that apply during construction, and it usually forms part of the conditions of consent.
Tree management plan. Longer term, typically for a site with a number of trees under ongoing management, such as a school, a strata scheme or a commercial property.
Post-incident report. Prepared after a failure, documenting what failed and why. Used in insurance matters and in neighbour disputes.
A single project can need several of these. A development with mature trees on a boundary will commonly need an impact assessment, a tree protection plan, and a separate condition report for any tree proposed for removal.
Why does the arborist’s qualification matter so much?
There is no general arborist licence in New South Wales. Arborists hold qualifications under the Australian Qualifications Framework rather than a licence, and the level matters.
- AQF Level 3 is the Certificate III qualification and is the benchmark for practical tree work: climbing, rigging, pruning and removal.
- AQF Level 4 is a supervisory qualification for advanced practical work.
- AQF Level 5 is the Diploma, and it is the qualification associated with consulting arborists who prepare formal assessments, risk assessments and reports.
Councils generally want the report signed by someone at Level 5. North Sydney Council, for example, states that reports must be prepared by a qualified arborist holding the Diploma of Horticulture (Arboriculture) at AQF 5, or with equivalent demonstrated experience in high-level tree assessment and diagnosis, and that the arborist must also be a Consultant Member of Arboriculture Australia or of the Institute of Australian Consulting Arboriculturists.
North Sydney Council also draws the distinction plainly: there is a real difference in qualification and skill between an arborist who prunes and removes trees and an arborist who diagnoses tree health and structure. Both are legitimate roles. They are not interchangeable on a report.
Chainsaw tickets, elevated work platform tickets and powerline clearance accreditations are all separate again. They are important for doing the work safely and lawfully. They are not substitutes for a consulting qualification on a report.
Requirements do differ between councils, so check what your council asks for before commissioning anything.
When will a Sydney council ask for a report?
You have applied to remove or heavily prune a protected tree
If the tree is protected under your council’s development control plan and no exemption applies, your application is a request for Council to depart from its own retention objectives. Council needs a reason it can defend. “It drops leaves” and “it blocks the view” are not reasons councils accept. Documented structural failure, disease, or unmanageable conflict with a building is.
You are claiming the tree is dead, dying or dangerous
Most Sydney councils exempt trees that are dead, dying or posing an imminent risk. In practice the exemption usually requires Council to be satisfied first, and where the tree is significant, councils commonly ask for an arborist’s report and sometimes testing before they will accept the claim. This is the situation where a report most often saves money, because it converts a contested judgement into documented evidence.
There are trees on or near a development site
This is the biggest single driver of arborist report work in Sydney. If you are building, extending or subdividing, and there are trees on the site or on adjoining land whose root zones extend into it, the consent authority will want to know what the build does to those trees.
AS 4970-2009, the Australian Standard for protection of trees on development sites, is the reference point. It sets out how to calculate a tree protection zone and a structural root zone from the tree’s trunk dimensions, and what may and may not happen inside those areas. Your report will map those zones over the proposed works, assess the impact of each element of the build, and specify the protection measures required at each stage.
Where the design encroaches into a protection zone, the report is where an alternative construction method gets proposed and justified. That is often the difference between a design being approved and a design being sent back.
You are dealing with a neighbour, an insurer or a strata committee
Reports are also used outside the council process: in neighbour disputes over overhanging branches or root damage, in insurance matters after a tree failure, and by owners corporations documenting that they have managed a known risk. In those settings the qualification of the arborist affects whether the report is treated as expert evidence.
What gets a report rejected?
Councils reject reports for predictable reasons.
The arborist is not qualified to the level the council requires. The most common cause, and the easiest to avoid by checking first.
The recommendation is not supported by the assessment. A report that describes a healthy tree in good structural condition and then recommends removal will not be accepted. The evidence has to lead to the conclusion.
Missing content the council specifically asks for. Councils publish what they want in a report. Some require a specific tree numbering system, a survey-accurate site plan, or particular fields completed. Reports that omit them get returned.
No consideration of retention. Councils are looking for evidence that retention was genuinely assessed. A report that considers only removal reads as a report written to a predetermined answer.
Nothing on replacement. Councils increasingly condition approvals on replacement planting, and many expect the report to address what should be planted and where.
Stale. Reports age. A report prepared for a lapsed application, or before a significant storm or a change to the design, may need updating rather than resubmitting.
Do you always need a report?
No, and a good arborist will tell you when you do not.
If the tree falls squarely inside a published exemption in your council’s controls, you do not need a report to remove it. If the tree is on the council’s exempt species list and the property is not heritage listed, the same applies. If the work is minor pruning within the limits your council sets, again no report.
The cost of a site visit to establish which category you are in is generally lower than the cost of commissioning a report you did not need, or of lodging an application that was never going to succeed. It is worth doing in that order.
How pruning is specified
Where a report recommends pruning rather than removal, the pruning specification is written to AS 4373-2007, the Australian Standard for pruning of amenity trees. That standard defines the pruning types by name, including deadwooding, crown thinning, crown lifting, selective pruning and reduction pruning.
This matters for two reasons. Councils condition approvals on the work being carried out to that standard, so the specification needs to be in that language. And a specification written in standard terms is much harder for a contractor to misinterpret on the day, which protects the tree and protects you.
How to prepare for the site visit
A little preparation makes the assessment faster and the report better.
Have the property details ready, including the lot and deposited plan numbers, which appear on your rates notice or title documents. If you are building, provide the architectural drawings, the survey plan and any landscape plan, ideally as scaled files rather than photographs of a printout. The arborist needs to overlay the proposed works on the trees, and that cannot be done accurately from a sketch.
Know what you actually want. “Something needs to be done about that tree” produces a vaguer report than “we want to know whether this tree can be retained if the extension goes where the drawing shows”.
Make sure the trees are physically accessible. An arborist needs to get to the base of the trunk, examine the root plate and often sound the trunk. A tree behind a locked side gate, inside a run with a dog in it, or buried in overgrown shrubbery adds a return visit.
Flag anything you already know. Previous storm damage, limbs that have come down, a change in the canopy over the last season, a neighbour’s complaint, or works done nearby in recent years are all relevant history that will not be visible on the day.
If adjoining trees are involved, let the neighbours know someone will be looking over the fence. It avoids an awkward conversation and it often produces useful information.
What happens after the report goes in?
The report supports a decision, it does not make it. No consulting arborist can guarantee a council approval, and any who offers to should be treated with caution.
Council will assess the report against its own retention objectives and may seek clarification, request additional information, or have its own arborist inspect and reach a different conclusion. Where the assessments differ, the quality of the documentation in your report is what carries the argument.
If approval is granted, expect conditions. Commonly these require that the work be carried out by a suitably qualified arborist, that pruning be carried out in accordance with AS 4373-2007, that protection measures from the tree protection plan be implemented and in some cases certified at stages, and that replacement planting be undertaken to a specification Council sets.
Reports also date. If an application lapses, if the design changes materially, or if a significant storm passes through between the assessment and the works, the report may need updating rather than resubmitting. Keeping a copy of the report, the approval and the conditions with your property records is worth doing, because the next owner or the next application will need them.
What to ask before you commission a report
- What is your AQF qualification level, and are you a consultant member of Arboriculture Australia or the Institute of Australian Consulting Arboriculturists?
- Have you prepared reports accepted by this specific council before?
- What exactly will the report cover, and does that match what the council asks for?
- Will you attend the site, or is this a desktop assessment?
- Is a survey plan required, and do I need to arrange it separately?
- What happens if Council comes back with questions?
- Is the fee fixed, and what does it include?
Ask the same questions of whoever will do the physical work, with the addition of insurance certificates and qualification evidence for the crew.
Sydney Tree Company can assess the tree first
The practical starting point is an assessment on site: confirming the species, checking your council’s current controls and mapping, and establishing whether an exemption applies, an application is needed, or a report is needed to support one.
Sydney Tree Company provides tree health inspection and evaluation, arborist advice, and assistance with council tree preservation paperwork, alongside tree removal, pruning, stump grinding and palm pruning across the Sydney metropolitan area.
Call 0431 732 265 to arrange a free quote and an on-site assessment.