DA Tree Impact Assessment Sydney
Arboricultural Impact Assessments (AIA) for Development Applications
An Arboricultural Impact Assessment (AIA) is an AQF Level 5 arborist report that assesses how a proposed development may affect existing trees and provides recommendations for tree retention, removal and protection during the Development Application process.
- AQF Level 5, QTRA and TRAQ qualified Consulting Arborists
- 32+ years' consulting experience
- Council-ready AIAs
- Prepared with reference to AS 4970
- Fast-track service available
Need an Arborist Report to Assess Your Development's Impact on Trees?
Arbor Express prepares AQF Level 5 Arboricultural Impact Assessments throughout Sydney for homeowners, architects, builders, developers, town planners and strata managers, giving councils independent arboricultural advice to support the Development Application.
Not sure whether an AIA or a different report is the right starting point? See our Tree Reports Sydney guide for how each report fits your project stage.
When Do You Need a Tree Impact Assessment?
An AIA is commonly requested where proposed buildings, excavation, driveways, retaining walls, services or level changes may affect retained trees, including for the projects listed.
- New homes and extensions
- Duplex and multi-dwelling developments
- Townhouses and residential flat buildings
- Commercial and industrial developments
- Schools, childcare centres, subdivisions and infrastructure projects
What Does the Assessment Include?
An AIA is prepared specifically for the proposed development and commonly assesses the items listed.
Each AIA concludes with practical recommendations on tree retention, removal, mitigation and protection to support the Development Application.
- Tree condition, species and retention value
- Proposed building footprints and excavation
- Retaining walls, services and level changes
- Tree Protection Zone (TPZ) and Structural Root Zone (SRZ) impacts
- Neighbouring and council trees, where relevant
- Assessment with reference to AS 4970
TPZ and SRZ Impacts
The Tree Protection Zone (TPZ) and Structural Root Zone (SRZ) are used to assess potential development impacts around retained trees under AS 4970. The TPZ assists in protecting tree health and viability, while the SRZ relates particularly to the tree's structural stability.
Minor encroachment into the TPZ may be acceptable where the impact can be appropriately managed; major encroachment generally needs more detailed justification and mitigation. Council assessment considers the actual arboricultural implications of the specific encroachment, not a fixed percentage.
Preliminary Assessment vs DA Tree Impact Assessment
Still at concept stage? See our Preliminary Arboricultural Assessment Sydney guide.
Need Root Investigation?
Where excavation raises uncertainty about the actual location of significant roots, we can arrange a non-destructive Tree Root Investigation and Mapping before the design or construction methodology is finalised.
Larger Sites and Native Vegetation
For larger sites, rural land or projects affecting more than individual retained trees, native vegetation and biodiversity legislation can apply alongside the AIA, particularly for subdivisions, larger clearing works or sites with habitat value. See our Flora and Fauna Assessments service.
What Happens After the AIA?
Findings typically carry forward into a Tree Protection Plan, ongoing Project Arborist supervision during construction, and Construction Tree Compliance through to project completion.
Why Choose Arbor Express?
For more than 32 years, Arbor Express has prepared arboricultural assessments for residential, commercial and infrastructure projects throughout Sydney, with reports tailored to the relevant development proposal and council requirements.
- AQF Level 5 Consulting Arborists
- Development impact assessment with reference to AS 4970
- TPZ/SRZ impact assessment
- In-house AirSpade root investigation
- Project Arborist capability for ongoing construction support
Need Your AIA Quickly?
Fast-track options are available for urgent Development Applications. Call us to discuss your timeframe.
0494 077 630Our Process
- 1Site inspection: we inspect all relevant trees and surrounding site conditions.
- 2Tree assessment: each tree is assessed for species, condition, health, structure and retention value.
- 3Development review: we review the proposed plans to identify potential impacts on retained trees.
- 4Impact assessment: construction impacts are assessed with reference to AS 4970, including TPZ and SRZ calculations where required.
- 5Recommendations: practical recommendations that balance development objectives with appropriate tree protection.
- 6Council-ready report: your completed AIA, prepared for submission with your Development Application.
Frequently Asked Questions
A tree impact assessment, formally an Arboricultural Impact Assessment (AIA), assesses how proposed construction may affect existing trees and provides councils with independent arboricultural advice to support Development Applications.
A Preliminary Arboricultural Assessment is prepared before design to identify constraints; an AIA is prepared once plans are drafted to assess the impact of that specific design.
Not automatically. An AIA examines opportunities to retain trees first, and only recommends removal where retention isn't reasonably achievable alongside the proposed development.
Yes. We can review amended plans and update the AIA's findings and recommendations to reflect the revised design.
Most AIAs are completed within a few business days of the site inspection, with fast-track options available for urgent Development Applications.
DA Tree Impact Assessments Across Sydney and NSW
Arbor Express prepares DA Tree Impact Assessments throughout Greater Sydney and surrounding NSW regions. Council requirements vary, and our location guides provide information about local tree controls and Development Application requirements for your area.
What Our Clients Say
Request a Tree Impact Assessment Quote
Need a tree impact assessment for your Development Application? Our AQF Level 5, QTRA and TRAQ qualified Consulting Arborists prepare Council-ready Arboricultural Impact Assessments throughout Sydney.