The quick difference (plain English)

Arboricultural Impact Assessment (AIA)

An Arboricultural Impact Assessment looks at how a proposed design could affect existing trees, and what needs to change or be managed so trees can remain viable after construction.

Read more on Arboricultural Impact Assessment.

Tree Management Plan (TMP)

A Tree Management Plan is the practical rulebook for the build. It sets out how to work near retained trees during demolition, excavation, and construction, without causing avoidable damage.

Read more on Tree Management Plan.



Tree Protection Plan (TPP)

A Tree Protection Plan is a scaled drawing that shows the protection measures on the site plan, including tree locations, protection zones, and where fencing and controls go.

Read more on Tree Protection Plan.



When each report is needed

Use this as a decision shortcut

Most projects fit one of these patterns:

• Design and approvals stage: Start with an AIA to confirm impacts, constraints, and what needs to change before plans are locked in.
• Permit conditions stage: Add a TMP when council wants a clear method for protecting retained trees during works.
• On-site setup stage: Use a TPP so everyone on site can see the protection layout at a glance.

Ordering the right report at the right stage is one of the simplest ways to reduce delays.

Why councils ask for different documents

Councils are usually trying to answer three questions:



• Will the proposed works damage trees, or cause decline later?
• What controls will stop avoidable damage during construction?
• Can the protection measures be verified on site?

AIA, TMP, and TPP line up to those three questions.

What each document typically includes

AIA inclusions

An AIA commonly covers:



• Tree condition and retention considerations
• Potential impacts from the proposed works
• Protection zones and key constraints
• Practical recommendations to reduce risk to tree viability post-construction
• Approval considerations relevant to the scope

An AIA is the “can this design work near these trees” document.

TMP inclusions

A TMP commonly covers:



• Site rules for working within protection zones
• Access routes, storage areas, and no-go zones
• Methods to reduce root damage during excavation and construction
• Timing and sequencing recommendations around high-risk works
• Monitoring and supervision requirements where needed for compliance

A TMP is the “how the site will behave around trees” document.

TPP inclusions

A TPP is typically a scaled plan showing:



• Accurate tree locations
• Tree Protection Zones and Structural Root Zones
• Fencing and signage locations
• Ground protection areas (where needed)
• Any other protection measures noted in the TMP

A TPP is the “show it on the plan” document.

How they work together on real projects

Example 1, home extension near established trees

• AIA confirms whether the footprint and excavation will likely cause unacceptable impacts.
• TMP sets the rules for demolition, excavation, and site access around retained trees.
• TPP shows fencing and protection on the plan so the builder can set it up correctly.



Example 2, multi-dwelling or townhouse development

• AIA is used early to prevent redesign later, especially where trees constrain setbacks, driveways, or services.
• TMP is often required as a permit condition to keep the build compliant.
• TPP reduces on-site confusion, especially with multiple trades and changing site conditions.



Example 3, approvals are done, but the site needs compliance controls

• TMP + TPP can be the priority set, particularly where the key risk is construction-stage damage.
• 

The standard that often sits behind tree protection on development sites

Tree protection on development sites is commonly guided by the Australian Standard AS 4970:2025, which sets out principles and processes for retaining and protecting trees during development.

Link: AS 4970:2025 Protection of trees on development sites

This matters because it creates a shared language across planning, consulting arborists, and construction teams, including terms like Tree Protection Zone and Structural Root Zone.



FAQs

What is the difference between an arborist report and an AIA?

“Arborist report” is a broad term that can mean several document types, depending on what council or the project needs. An Arboricultural Impact Assessment (AIA) is a specific report focused on how a proposed design and construction impacts existing trees, and what controls or design changes are needed to retain them.



A practical way to think about it:

• Arborist report = the umbrella term
• AIA = the impact-focused report used to support design and approvals

Can a Tree Protection Plan be included within another report?

Yes, a TPP is often included as a plan within a Tree Management Plan, or attached as an appendix. Some councils or permit conditions prefer it as a standalone plan so it can be issued to builders and displayed on site without the full report.

If the scope is construction-stage compliance, a clear pairing is:

• Tree Management Plan for controls
• Tree Protection Plan for the scaled layout



Do I need a TMP if my works are outside the Tree Protection Zone?

Often, if all works and site activities are genuinely outside the Tree Protection Zone, a TMP may not be required. The common issue is that “works” includes more than just the finished footprint.

A TMP can still be relevant if there will be:

• Access routes, turning circles, or temporary works near trees
• Material storage, washout, or spoil placement near protection zones
• Trenching for services that passes near trees
• Compaction risks from repeated vehicle movement
• Changes in levels, drainage, or soil conditions near root zones
• 

When should tree protection fencing go in?

Tree protection fencing should be installed before any activity that could affect the tree area, including demolition, excavation, earthworks, or bringing heavy machinery onto site. It is normally set up after the site is set-out and verified, then kept in place and maintained for the duration of high-risk works.



What site information is needed to prepare a TPP accurately?

A TPP is only as good as the drawings and site information behind it. The usual inputs include:



• Current feature and level survey
• Proposed site plan and architectural drawings
• Civil drawings, including levels, drainage, and pavement build-ups (if applicable)
• Tree locations and identifiers that match the consultant’s assessment
• Proposed access routes, laydown areas, and scaffolding zones
• Any known service runs, trenching routes, and piering locations
• Construction staging, especially where protection needs to change over time

Common mistakes

Ordering the wrong document first

The most common delay is starting with a TMP or TPP when the design still has major conflicts. If the footprint is not viable, the project can loop back into redesign.



Treating a tree protection plan like a generic site note

A TPP needs to match the actual site layout and construction method. If fencing and access routes are vague, it becomes hard to enforce on site.



Inconsistent tree numbering across plans

When the AIA, architectural drawings, and TPP do not match tree IDs, it creates instant confusion for planners, builders, and site supervisors.



Starting works before tree protection is installed

Even small early works can cause root damage. Once roots are compromised, the rest of the documentation may not prevent decline.



Ignoring permit conditions and staging

Some approvals require specific steps at set points in the build. Missing the timing can trigger stop-work actions or rework.

Avoidable compliance issues are usually process issues, not tree issues.



Quick checklist and next steps

Checklist, before you brief an arborist

• Confirm your project stage: concept design, lodged, approved, or on-site.
• Confirm who the decision-maker is: council planner, private certifier, or project superintendent.
• Gather current drawings: site plan, floor plans, proposed levels, driveway and service runs.
• Identify the high-risk works: excavation, demolition, piering, trenching, or grade changes.
• Confirm what council is actually asking for: AIA, TMP, TPP, or a combination.

What to do next

• For an impact-first scope, start with an Arboricultural Impact Assessment.
• For a construction-control scope, start with a Tree Management Plan and align it to a Tree Protection Plan.

Wrap-up

AIA, TMP, and TPP are different tools for different moments in the project. The clean approach is simple, assess impacts early, lock in controls before works start, and make the on-site layout unmissable.



Enquire
Use the contact form to confirm which report your project needs and what to prepare before a site visit.