RFI - Attachment 3 - Arborcultural Impact Assessment Report · 132003.221108.3

10.1.2 Considerations
Under AS4970-2025 the TPZ is described as:
The Tree Protection Zone (TPZ) is defined in Clause 1.3.19 of AS 4970:2025 as:
"specified zone above and below ground and at given offsets from the trunk set aside to protect a tree’s roots and crown where these might be damaged
by development."
    • The NRZ is the starting point for determining the TPZ.
The TPZ should be determined using various considerations in relation to the tree and proposed encroachments. Additionally:

The Structural Root Zone (SRZ) is described as:
is defined in Clause 1.3.17 of AS 4970:2025 as:
“Theoretical area around the base of a tree required for the tree’s stability in the ground.”
The woody root growth and soil cohesion in this area are necessary to hold the tree upright. The SRZ is nominally circular with the trunk at its centre
and is expressed by its radius in metres. This zone considers a tree's structural stability only, not the root zone required for a tree's vigour and long-term
viability, which will usually be a much larger area ‘(TPZ)’.




                               Tree Report: (AIA-27 Bayview NH-120226)                            Report Number:     (001)
                               Prepared by (Sam Carr – Specialist Arbor Services Pty Ltd)                        Page 26 of 26