Service
Arboricultural Impact Assessments (AIA)
The report councils require when construction encroaches on the root zone of protected trees — what your build does to each tree, and what has to change.
Scales with site size and tree numbers. Fixed quote after we review your plans.
Who this is for
- Owners and developers lodging a development application
- Builders whose plans encroach on a protected tree’s root zone
- Architects and town planners resolving tree constraints early
- Anyone issued an information request by council seeking an AIA
What you get
- Tree survey with an individual tree data schedule
- Tree Protection Zone (TPZ) and Structural Root Zone (SRZ) calculations
- Retention value and useful life expectancy (ULE) rating per tree
- Encroachment analysis against your architectural and civil drawings
- Assessment of impacts from excavation, level changes, services and site access
- Recommended design modifications to retain viable trees
- Tree protection specifications and plan
Standards applied
Reports are prepared against the standards and instruments assessors expect to see referenced.
- AS 4970-2009 Protection of trees on development sites
- AS 4373-2007 Pruning of amenity trees
- Brisbane City Plan 2014 vegetation codes and overlays
Arboricultural Impact Assessment — questions
When do I need an Arboricultural Impact Assessment?
Brisbane City Council requires one where construction is expected to significantly impact protected vegetation — most commonly when works fall inside the root zone of a protected tree. If council has issued an information request asking for an AIA, that is your trigger.
What is a TPZ, and why does it matter?
The Tree Protection Zone is a radius calculated under AS 4970 as twelve times the trunk diameter at breast height. It defines the area that must be protected for the tree to survive. Encroachment beyond 10% of the TPZ area generally requires justification — which is precisely what the assessment provides.
Can an AIA get my design approved with the tree removed?
Sometimes. Where a tree has genuinely low retention value — poor health, poor structure, short useful life expectancy — the assessment can build an evidence-based case for removal. What it cannot do is manufacture a justification for removing a healthy, high-value tree. An honest read early is far cheaper than a redesign after refusal.
Should I get this before or after I finalise my plans?
Before. Tree constraints identified at concept stage are a design input. Identified after the drawings are done, they become an expensive redesign.
Related
Often needed alongside this
Tree Protection Plan
The drawing and specification that keeps retained trees alive through construction — and keeps you compliant with the conditions on your approval.
Read more →Project Arborist
The named arborist on your approval — supervising works near retained trees, attending hold points, and signing off what council requires signed off.
Read more →Arborist Report
A written assessment of your tree by an AQF Level 5 arborist — the document councils ask for when you apply to prune or remove protected vegetation.
Read more →Get started
Request a quote for arboricultural impact assessment
Tell us the property and what council has asked for. You will get a fixed price and a realistic timeframe — same business day.
- No obligation and no pressure
- Honest answer if you don't need the report
- Fixed price, quoted before any work begins
Enquire — Arboricultural Impact Assessment
Tell us what you need and you will hear back same business day. No obligation, and a fixed price before any work starts.
Not sure what you need?
Describe the situation and you will get a straight answer about which report your council actually requires — including when the answer is that you do not need one.