Arborist Reports Explained: When Do You Actually Need One?

If you own property in Wollongong, there is a good chance you have a tree on your block that is large, mature, or close to a building. Whether you are planning to remove it, prune it, build near it, or simply want to know if it is safe, you may be told you need an arborist report. This guide explains what these reports are, when they are genuinely required, and how to get the most value from one in the Wollongong local government area in 2026.

What Is an Arborist Report?

An arborist report, sometimes called an arboricultural report or tree assessment, is a written document prepared by a qualified arborist. It records the species, size, health, structural condition, and location of one or more trees, and provides professional recommendations based on that assessment.

In New South Wales, a credible report is usually prepared by an arborist holding at least an AQF Level 5 Diploma in Arboriculture. Many councils, including Wollongong City Council, expect this level of qualification for reports that support development applications or tree removal requests involving significant trees.

What a Typical Report Includes

While the format varies depending on the purpose, most reports contain:

• Tree identification, including common and botanical name
• Height, canopy spread, and trunk diameter (often measured at 1.4 metres above ground)
• Health and vigour ratings, including signs of pests, disease, or decay
• Structural defects such as included bark, cavities, cracks, or root damage
• Useful life expectancy and retention value
• Risk assessment, often using a recognised method such as QTRA or TRAQ
• Photographs and a site plan showing tree locations
• Recommendations for removal, pruning, retention, or protection measures

Common Types of Arborist Reports

Not all reports serve the same purpose. Knowing which type you need can save time and money.

Tree Risk Assessment

This report focuses on the likelihood of a tree or branch failing and the consequences if it does. It is commonly requested when a tree leans, has dead limbs, shows fungal growth at the base, or has been damaged by a storm. Wollongong's escarpment winds and coastal weather events make this a frequent concern.

Tree Removal or Pruning Justification Report

When a tree is protected under council rules, a report may be needed to justify removal or major pruning. It explains why the work is necessary, such as structural failure, disease, or damage to property.

Development Application (Arboricultural Impact Assessment)

If you are building a new home, adding an extension, installing a pool, or subdividing, an Arboricultural Impact Assessment (AIA) evaluates how construction will affect nearby trees, including those on neighbouring properties. It often includes a Tree Protection Plan showing fencing, root protection zones, and construction methods.

Property Damage or Insurance Report

Where tree roots are suspected of damaging drains, retaining walls, driveways, or foundations, a report can document the cause and support insurance claims or neighbour disputes. It may need to be paired with a structural engineer's or plumber's findings.

When Do You Actually Need an Arborist Report in Wollongong?

Not every tree job requires a formal report. The need depends on the tree, its location, and what you plan to do. Below are the most common situations.

Tree Removal or Pruning Under Council Controls

In Wollongong, tree work is regulated through the Wollongong Development Control Plan and the state planning framework, including the Biodiversity and Conservation SEPP. Many trees on private land require council approval before removal or significant pruning, depending on size, species, location, and zoning. Council may request an arborist report, particularly for larger trees, trees near dwellings, or removals where the reason is not obvious, such as a dead tree.

Always check with council before any work begins. Unauthorised removal of a protected tree can attract substantial penalties.

Trees in Heritage, Environmental, or Conservation Areas

Properties in heritage conservation areas, near riparian corridors, in coastal zones, or adjoining bushland on the escarpment may face stricter controls. Native vegetation, threatened ecological communities, and habitat trees can trigger additional requirements, and a report is often necessary to support any application.

Development and Building Work

If construction, excavation, or landscaping is planned within the root zone of a significant tree, council will often require an AIA with the development application. A general rule used in Australian Standard AS 4970 (Protection of trees on development sites) is to calculate the Tree Protection Zone based on trunk diameter. Encroachment of more than 10 percent into this zone needs assessment by a qualified arborist.

Safety Concerns and Liability

You may not be legally required to obtain a report for a hazardous tree, but as a property owner you have a duty of care. If a tree on your land drops a limb onto a neighbour, a car, or a person, having documented professional advice can demonstrate that you acted responsibly. A risk assessment is a sensible step if you notice:

• Large dead branches or a thinning, declining canopy
• Mushrooms or brackets growing at the base or on the trunk
• Cracks, splits, or hollows in the trunk or major limbs
• A sudden change in lean or lifted soil around the roots
• Recent storm damage or nearby construction that has disturbed roots

Neighbour Disputes and Land and Environment Court Matters

Under the Trees (Disputes Between Neighbours) Act 2006, neighbours can apply to the NSW Land and Environment Court for orders about trees that are causing damage or posing a risk of injury. An independent arborist report is often central evidence in such cases. Even before legal action, a report can help neighbours reach agreement based on facts rather than opinion.

Real Estate and Property Purchases

Buyers sometimes commission a report before purchasing a property with large mature trees, especially if the trees are close to the house. Sellers may also obtain one to demonstrate that trees have been professionally assessed and to avoid surprises during negotiations.

When You Probably Do Not Need a Report

Many routine jobs do not require a formal report. Minor pruning of a small tree, removing a small exempt species, or general maintenance such as deadwooding may be allowed without approval, provided the tree is not protected. Some species are exempt from controls, but exemptions depend on local rules, so verify with council rather than assuming.

If a tree poses an immediate danger, such as a limb or trunk that has partly failed, emergency works may be permitted in certain circumstances. Document the situation with photographs and engage a qualified arborist right away. The NSW 10/50 Vegetation Clearing Code applies only in designated bushfire-prone areas and has strict conditions, so do not rely on it without confirming eligibility.

How to Get a Quality Arborist Report

Choose a Qualified, Independent Arborist

Look for a consulting arborist with an AQF Level 5 qualification or higher, current public liability and professional indemnity insurance, and membership with a recognised body such as Arboriculture Australia or the Institute of Australian Consulting Arboriculturists (IACA). Ask to see sample reports and confirm they have experience dealing with Wollongong City Council requirements.

Where possible, use an arborist who is independent of the tree removal company. A consultant who does not stand to profit from the work provides greater credibility, particularly if the report will be used in a council application or dispute.

Be Clear About the Purpose

Tell the arborist exactly why you need the report and who will read it. A report for council, an insurer, or a court has different requirements from one prepared for your own peace of mind. Providing site plans, survey details, or proposed building plans helps the arborist produce accurate recommendations.

Understand the Costs and Timeframes

Costs vary widely depending on the number of trees, access, and complexity. A basic single-tree assessment typically costs a few hundred dollars, while a comprehensive AIA for a development site can run into the thousands. Turnaround times commonly range from several days to a couple of weeks. Allow extra time if council approvals depend on the report.

What to Do After You Receive the Report

1. Read the recommendations carefully and ask the arborist to clarify anything unclear.
2. Check whether council approval is needed before carrying out any recommended work.
3. Lodge your application or permit request with the report attached, if required.
4. Engage a qualified, insured tree contractor to carry out the work to AS 4373 (Pruning of amenity trees).
5. Keep the report and all related documentation, as it may be useful for future insurance, sale, or dispute purposes.

Local Considerations for Wollongong Property Owners

Wollongong's mix of coastal suburbs, escarpment slopes, and older established neighbourhoods creates unique tree management challenges. Steep sites can make root stability a concern, while salt-laden winds and storm events can stress coastal trees. Native species such as Illawarra flame trees, figs, and eucalypts can grow very large, and their root systems may interact with drains, retaining walls, https://spencerjpjh007.valiantfield.com/posts/best-methods-for-removing-unsightly-ivy-from-mature-trees and footings. Large fig trees in particular are common in the region and often attract special attention due to their size and root spread.

Climate patterns in recent years have also brought heavier rainfall events and stronger storms, which has increased demand for risk assessments. Having a current assessment of significant trees on your property is a practical way to stay ahead of problems.

Final Thoughts

An arborist report is not always mandatory, but it is often the most reliable way to make an informed decision about a tree. You are most likely to need one if the tree is protected, if you are developing your property, if safety is a concern, or if a dispute is involved. Before you cut, prune, or build, check Wollongong City Council's current requirements, speak with a qualified consulting arborist, and keep thorough records. Doing so protects your property, your neighbours, and the urban canopy that makes the Illawarra such a desirable place to live.

Wollongong Tree Removal Pros

106 Gipps St, Wollongong NSW 2500

(02) 4210 5945