Design with reliable tree information
The design team can work from measured tree data and mapped Notional Root Zones and Structural Root Zones, rather than assumptions.
Preliminary Arboricultural Reports · Melbourne
Know the trees before the design is fixed.
Clear tree constraints. Better design decisions.
A Preliminary Arboricultural Report identifies the trees on and near a development site, assesses their condition and retention value, and maps the root-zone constraints that should inform early design decisions.
Discuss your project
Early project information
Make tree constraints visible early.
A Preliminary Arboricultural Report is prepared at the beginning of a project, after the available site survey information has been reviewed. It gives the design team quantitative and qualitative information about the trees that may influence the proposal.
The purpose is not to stop development. It is to identify which trees are suitable for retention, where root-zone constraints apply and what design responses should be considered before the layout, levels, access and service routes are fixed.
What the report does
A clear starting point for the design team.
The report records the trees within and near the site, explains their condition and value, and identifies the Notional Root Zones that may influence development.
Each assessed tree is assigned a preliminary retention value. Trees may be identified as suitable for retention, suitable for transplanting, or not worthy of retention. The findings are presented in a written report and on a tree plan so the project team can see the constraints before design decisions become difficult to change.
The preliminary report process
From site information to design direction.
- 01
Confirm project scope
Review the property, proposal, project stage and requirements of the design team or relevant authority.
- 02
Review the feature and level survey
Confirm that tree locations, site levels, structures and relevant site features are available for assessment and mapping.
- 03
Inspect and assess trees
Record the tree species, dimensions, health, structure, age class, useful life expectancy and site context.
- 04
Assign retention values
Consider the condition, suitability, significance and future contribution of each tree to the site and surrounding landscape.
- 05
Calculate root-zone constraints
Calculate the Notional Root Zone and Structural Root Zone dimensions that should be considered during early design.
- 06
Prepare the report and plan
Present the tree inventory, retention values, root zones, plan information and preliminary recommendations in a coordinated document.
- 07
Guide early design decisions
Use the findings to test layout options and identify where design changes, further investigation or later impact assessment may be required.
What the report contains
Site-specific evidence, clearly organised.
- Site, proposal and relevant planning context
- A numbered tree inventory, including relevant neighbouring trees
- Botanical and common names, dimensions, health, structure and age class
- Useful life expectancy and landscape, heritage, ecological or habitat considerations
- Preliminary retention values for each assessed tree
- Calculated Notional Root Zones and Structural Root Zones
- A plan showing tree locations, identifiers and root zones
- Early design guidance, recommendations and next steps
Why it helps
Focus effort on the right trees
Retention values help the project team distinguish important tree constraints from trees that should not drive the layout.
Test options before the layout is fixed
Building footprints, access, levels and services can be considered while practical alternatives remain available.
Reduce avoidable redesign and delay
Early information can reveal conflicts before detailed drawings are prepared or a planning application is lodged.
Set a clear pathway to the next stage
The report identifies whether an Arboricultural Impact Assessment, root investigation or tree protection documentation is likely to be needed.
Root-zone constraints
See the space the tree needs.
The Notional Root Zone identifies the area considered important for tree viability. The Structural Root Zone identifies the area required for structural stability.
These zones can be overlaid on architectural, engineering, landscape and service drawings so the project team can compare options and identify where further assessment may be required.
The calculations and terminology align with AS4970:2025 Protection of trees on development sites.
The final protected area and construction-phase measures are confirmed later, once the development layout and likely impacts are known.
Preliminary recommendations
Early recommendations can change the outcome.
Work with the existing site
Where practical, use existing footprints, access points and disturbed areas to reduce new encroachment into important root zones.
Adjust the design
Shift the building, slab edge, footing system, excavation, finished levels or service route where a sympathetic alternative is available.
Investigate uncertainty
Targeted root investigation may be recommended where the location or significance of roots could materially affect the design response.
Preliminary report or impact assessment?
Different reports for different project stages.
Preliminary Arboricultural Report
Prepared during early planning, before the design is fixed. It identifies the trees, retention values and root-zone constraints that should inform the layout.
Arboricultural Impact Assessment
Prepared after the design has progressed. It assesses likely development impacts and explains the design modifications and protection measures required for retained trees.
Some projects require both reports as the design moves from feasibility and concept planning into a planning application.
Who the report supports
Useful information for the whole project team.
- Developers, architects and building designers
- Residential property owners
- Project managers and consultant teams
Information to provide
Start with what is available.
- Property address and a short description of the proposal
- Feature and level survey, if available
- Concept or developed architectural drawings
- Civil, hydraulic, service, landscape or construction drawings
- Council requests, permit conditions or further information requests
- Previous arboricultural reports or correspondence
- Required timeframe and current project stage
Frequently asked questions
Preliminary report questions.
When should I obtain a Preliminary Arboricultural Report?
Ideally after the feature and level survey is available and before the development layout is fixed. This gives the design team the greatest opportunity to respond to tree constraints.
Do I need drawings before the site inspection?
A feature and level survey is the most useful starting point. Concept drawings are helpful when available, but the report can be prepared before a detailed design exists.
Will neighbouring trees be included?
Relevant neighbouring trees can be assessed where they may influence the site or proposed works and where lawful access and suitable observations are available.
Is this the same as an Arboricultural Impact Assessment?
No. A preliminary report identifies early constraints before the design is fixed. An impact assessment evaluates a developed proposal against the trees and root zones.
Can this report support a tree removal permit?
The report may provide useful tree information, but a removal application may require a different site-specific scope depending on the relevant planning scheme, overlay or local law.
Does an AS4970:2025 aligned report guarantee approval?
No. The report provides arboricultural evidence and professional recommendations. Planning and permit decisions remain with the relevant authority.
Start with the site
We will confirm the right report.
Share the property address, project stage and any survey or design information currently available.
[email protected] 0401 766 127Consulting across Melbourne & Victoria
Subject to service-area eligibility.
Service area note: Consulting work cannot currently be accepted for properties within Maroondah municipality due to a professional conflict-of-interest requirement.