New Australian Standard for Protection of Trees on Development Sites and Adjoining Properties

Introduced in November 2009, the Australian Standard for the protection of trees on development sites and adjoining properties (AS 4970) has been causing headaches for many of our clients.

As planning consultants, our aim is to avoid these headaches and we provide the following general overview of the new Standard and offer some tips to assist you and minimise your risk when purchasing your next property.

How do these controls vary from the old controls?

• They are designed to better protect quality trees.
• Previously, a development could encroach within a defined Tree Protection Zone (TPZ) by up to 33 percent, without the need for further assessment or analysis.
• Now, a development can only encroach within a defined TPZ by up to 10 percent, without the need for further assessment or analysis.

What trees do these controls apply to?

All trees on your site, on the nature strip and all trees on adjoining properties.

How do you calculate the Tree Protection Zone (TPZ)?

To determine the TPZ for most trees, you simply measure the diameter of the trunk of the tree at approximately 1.4 metres above ground level and multiply this diameter by 12.

What are the risks?

Quite simply, if a tree is unable to be removed and the proposal unreasonably encroaches on the TPZ, then your site may not be able to be developed to the extent you have proposed.

What to consider when looking for you next development site?

• Don’t assume that you can remove all trees from your site.
• To retain feature trees on site can be a significant benefit to demonstrating the proposal is site responsive and successfully integrates into the existing neighbourhood character.
• If the tree looks healthy with a good form and structure, it is likely that Council will desire to retain the tree.
• A tree may not be as healthy or offer as good form or structure as other trees, however it may offer a broader value to the neighbourhood and again, there may be pressure from Council to retain the tree.
• Trees on adjoining properties can cause the most problems, as the trees are not yours to remove.
• If a tree is adjacent to the boundary of the site you are looking at purchasing and it is likely to be within close proximity of your proposed development, then consider approaching the owner of the tree prior to purchase, to determine if they would consider removing the tree, even at your cost.
• If you propose to encroach on the TPZ by more than 10 percent, then appropriate measures must be taken to ensure the tree remains healthy and sometimes, depending on the tree, this may simply not be possible.

Our involvement, in consultation with a suitably qualified Arborist, early in the planning process will minimise your risk and maximise your chances of gaining a planning permit.

For more information and to see how we can help you, contact us or call us directly today on 03 9596 9000.