A Guide to AS 4970-2009: Protecting Trees on Development Sites

When planning a development project, one of the often-overlooked elements is the preservation of trees. However, trees not only contribute to the environment but can also impact the success of a project. AS 4970-2009, a key Australian standard, provides guidelines for the protection of trees on development sites, ensuring they remain healthy and integrated into the landscape.

What Are Tree Protection Zones (TPZs)?

A cornerstone of AS 4970-2009 is the establishment of Tree Protection Zones (TPZs). These zones are designed to protect the roots and canopy of trees during construction. TPZs are calculated based on the size of the tree trunk, and they help define the area around a tree where no construction activities or root disturbance should take place, without prior approval from the project arborist.

This includes activities like excavation, soil compaction, and the placement of materials. Properly respecting TPZs is essential to prevent irreversible damage to health and structure of trees that could result in their decline or removal.

Developer Responsibilities

For developers, understanding and implementing the guidelines of AS 4970-2009 is not just about following legal requirement, it’s about protecting the long-term health and structure of the trees on development sites.

Developers must:

• Assess and map out TPZs on site plans before construction begins.
• Implement Tree Protection Fencing (TPF) to keep construction activities outside the TPZ.
• Minimize soil disruption in the tree’s protection zone during construction.
• Work closely with a qualified project arborist to develop a Tree Protection Management Plan (TPMP) for preserving trees on development sites.
• Engage the project arborist for all TPZ site supervision

The Benefits of Compliance

By following AS 4970-2009 guidelines it can save developers significant costs by avoiding damage to trees that would otherwise lead to costly removals or replacements. Additionally, trees add value to properties by enhancing aesthetic appeal and supporting local biodiversity. 

Incorporating tree protection fencing and a Tree Protection Management Plan into your development process, as outlined by AS 4970-2009, ensures that you not only comply with Australian planning standards but also create a more valuable, sustainable property. By taking the necessary steps to protect trees, developers contribute to long-term community health and urban canopy cover.