Before doing any building or renovation work, it’s important to consider the potential impact to the trees on, and around, your property. Trees are often damaged and even killed during construction work. However, some careful planning in the early stages and consultation with a qualified Arborist, can minimise damage and allow you to enjoy your trees long into the future.
Firstly, decide which trees you would like to keep in accordance with your new plans. If you have a much-loved tree that simply must stay, you may need to alter your designs to properly accommodate the tree and its root system. Don’t assume a tree will be fine if there’s nothing built immediately around it – a tree’s root structure can travel a long way and is integral to its health and survival and therefore must be properly accounted for.
It’s advisable to consult with a qualified Arborist at this stage, who can help identify any potential issues with your plans, advise on the trees that will have the greatest chance of survival and let you know exactly what’s possible. This knowledge in the initial stages may save you the hassle of costly delays and having to have designs reworked down the track.
Once you’ve identified the trees that you want to keep, the Arborist will calculate the ‘Tree Protection Zone’ for your particular tree based on the Australian Standard AS4970-2009 Protection of Trees on Development Sites recommended calculations.
This measurement determines the area that the tree will require to remain healthy and stable, and will inform your architect or builder exactly how far from your tree works should be kept so as not to damage the tree.
A rough guide to working out the tree protection zone is to measure the diameter of the tree trunk at breast height and multiply that number by 12. This is the number of centimetres from the trunk that the tree will need to remain healthy. Again, it’s best to get the advice of a qualified Arborist as every tree will be different.
Mark out and fence off the area of the tree protection zone. Clearly communicate with your builder which trees you want to be kept so that there’s no accidental removal of the tree and ensure they’re made aware of what they should and shouldn’t do. Having heavy building equipment around a tree and stacking bricks and other materials around the base of a tree can cause compaction of the soil that can be detrimental to its health as it essentially starves the tree of oxygen.
Compaction of the soil immediately surrounding the tree, cutting the tree’s roots and changing the ground level around a tree during construction are three of the most common causes of damage and death of a tree. Chemicals and paint poured around the base of a tree can also be detrimental to the tree’s health and should always be avoided.
It’s important to note that your local council may require a tree to have a tree protection plan if you’re doing a new build and there are trees that need to be retained. If a tree is protected, there are strict laws about what you can and can’t do, and failure to comply with these laws can lead to prosecution and heavy fines. To find out if your property has protected trees, contact your local city council.
If you’re building or renovating and would like some advice from a qualified Arborist about how to best protect your trees, contact Aussie Trees today.