Standard
Track updates
AS 4970:2025
[Current]Protection of trees on development sites
AS 4970:2025 provides guidance on the principles and processes involved in retaining, protecting, and integrating trees on development sites
Published: 30/05/2025
Pages: 33
Table of contents
Cited references
Content history
Table of contents
Header
About this publication
Preface
Introduction
1 Scope and general
1.1 Scope
1.2 Normative references
1.3 Terms and definitions
2 Planning and the tree protection process
2.1 General
2.1.1 Relevant authorities
2.1.2 Tree protection process
2.2 Planning
2.2.1 Site survey
2.2.2 Preliminary tree assessment
2.2.3 Preliminary arboricultural report (PAR)
2.2.4 Development design and review
2.2.5 Arboricultural Impact Assessment (AIA)
2.2.6 Tree Protection Specifications (TPS) and Tree Protection Plan (TPP)
3 Determining protection zones
3.1 Tree Protection Zone (TPZ)
3.2 Calculating the Notional Root Zone (NRZ)
3.3 Determining a Tree Protection Zone (TPZ)
3.3.1 General
3.3.2 Considerations in determining the TPZ
3.3.3 Crown management
3.3.4 Minor NRZ encroachment
3.3.5 Moderate NRZ encroachment
3.3.6 Major NRZ encroachment
3.4 Structural Root Zone (SRZ)
4 Tree protection measures
4.1 General
4.2 Activities generally excluded from the TPZ
4.3 Protective fences
4.4 Signs
4.5 Other tree protection measures
4.5.1 General
4.5.2 Trunk and branch protection
4.5.3 Ground protection
4.5.4 Root protection during work within the TPZ
4.5.5 Installing underground services within the TPZ
4.5.6 Scaffolding
4.6 Maintaining the Tree Protection Zone (TPZ)
5 Monitoring and certification
5.1 General
5.2 Tree Protection Specifications (TPS) and Tree Protection Plan (TPP)
5.3 Pre-construction
5.3.1 Tree removal and pruning
5.3.2 Installing tree protection fences and other protection measures
5.4 Construction stage
5.4.1 General
5.4.2 Site establishment
5.4.3 Demolition and construction work
5.4.4 Landscape work
5.4.5 Practical completion
5.5 Post-construction
5.5.1 Defects liability period
5.5.2 Final certification
Appendix A
A.1 General
Appendix B
B.1 Introduction
B.2 Background biology
B.2.1 General
B.2.2 Roots
B.2.3 Trunks and branches
B.2.4 Leaves
B.3 Effects of development on trees
B.3.1 General
B.3.2 Crown damage
B.3.3 Trunk damage
B.3.4 Root damage
B.4 Conclusions
Appendix C
C.1 Sign example
Bibliography
Cited references in this standard
Content history
[Superseded]
[Superseded]
AS 4970-2009 REC:2020
DR AS 4970:2024