A tree protection zone (TPZ) is the area around a tree that has to stay clear of machinery, parking, storage and digging so the roots survive. Under Australian Standard AS 4970-2009, its radius is 12 times the trunk diameter, with a minimum of 2 metres.
On a demolition it comes up twice: whether you need a council permit to remove or lop a tree, and how the trees you're keeping (yours, a neighbour's or the street's) are fenced off before machines arrive. Both are sorted before demolition day, not on it.
Here's how the zone is measured, when a tree permit is needed and what's off-limits inside the zone.
What a tree protection zone is
A tree protection zone is an exclusion area drawn around a tree on a building or demolition site. It's set out in AS 4970-2009, Protection of trees on development sites, which councils use as their reference when they assess tree protection. Inside the zone, nothing is allowed that could damage the roots or compact the soil over them.
Inside the TPZ sits a smaller area called the structural root zone (SRZ): the roots closest to the trunk that hold the tree up. Damage there can leave a tree unstable, so it's the part of the zone that's hardest to justify working in.
Two things it isn't:
- It isn't a permit. The zone describes how a tree is protected on site. Whether you can remove or lop a tree at all is a separate question (see below).
- It isn't only about the trunk. Roots spread well past the canopy edge on many trees, which is why the zone is measured from trunk size rather than by eye.
How big the zone is
The radius is the trunk diameter, measured at 1.4 metres above ground, multiplied by 12. It's measured outward from the centre of the trunk at ground level. The minimum is 2 metres, and the Standard caps it at 15 metres.
| Trunk diameter | TPZ radius |
|---|---|
| 16 cm or less | 2 m (the minimum) |
| 20 cm | 2.4 m |
| 50 cm | 6 m |
| 75 cm | 9 m |
| 100 cm | 12 m |
| 125 cm or more | 15 m (the cap) |
A tree with a 40 cm trunk works out to 0.4 × 12 = 4.8 metres, so the zone is a circle roughly 9.6 metres across. That's why a single established tree can take up much of a front yard, and why it matters where the excavator and trucks go.
When the work has to enter the zone
Sometimes the footprint of a new build, a driveway or demolition access cuts into a zone. Banyule City Council describes an encroachment of 10% or more of the zone as a "major encroachment", and says works there may not be permitted depending on severity. A smaller encroachment can be acceptable under AS 4970, and Wyndham, for example, requires its council arborist's consent for any modification to a zone. Where the numbers are tight, an arborist assesses it, not the demolisher.
When a tree permit is needed
Whether a tree can be removed or lopped depends on the tree and the planning controls on your property, not on the demolition itself. In Victoria these controls are layered, and each sets its own trigger:
| Control | What it requires |
|---|---|
| Vegetation Protection Overlay (VPO) | A permit to remove, destroy or lop vegetation specified in the overlay's schedule, unless an exemption applies |
| Environmental Significance Overlay (ESO) | Generally a permit to remove, destroy or lop vegetation, with exemptions; an arborist's report may be requested |
| Significant Landscape Overlay (SLO) | Generally a permit to remove, destroy or lop vegetation, with exemptions that vary by area |
| Heritage Overlay | A tree permit only where the schedule lists tree controls for that heritage place |
| Native vegetation rules (Clause 52.17) | Usually a permit to remove, destroy or lop native vegetation, with limited exemptions such as planted garden trees |
| Council local laws | Varies by council. Some protect trees above a set size and also regulate work near them |
The Mornington Peninsula is a good example of how local this gets. Schedule 1 to the Vegetation Protection Overlay applies to township areas such as the Mount Eliza escarpment and parts of Mornington and Mount Martha, and requires a permit to remove, destroy or lop vegetation unless an exemption applies. Those exemptions are specific and conditional, so don't assume yours applies.
Don't remove a tree to "make it easier" before you've checked. Removing or lopping a protected tree without a permit is the mistake owners most often regret. Ask your council which overlays and local laws apply to your property, and get any permit sorted before the tree comes down.
What's not allowed inside the zone
Councils spell out what happens around a protected tree during demolition and construction. Wyndham City Council requires temporary fencing around the full perimeter of every zone before any buildings, works or demolition begin, at least 1.5 metres high and kept in place for the whole job. Flagging and bunting aren't accepted as fencing. Banyule also asks for signage and ground protection such as mulch.
| Activity | Inside the zone |
|---|---|
| Parking vehicles or plant | Not allowed |
| Refuelling, or storing fuel, oil and chemicals | Not allowed |
| Stockpiling materials, debris, soil or construction waste | Not allowed |
| Storing equipment and tools | Not allowed |
| Stripping soil, changing levels, filling or open trenches | Not allowed |
| Fixing anything to the tree, or using it as a support | Not allowed |
The practical effect is that the zone has to be settled before demolition day. Where the excavator parks, where the trucks load and where the material is sorted all depend on where the fences go.
Your trees, your neighbour's and the street's
Trees on your property
If a tree is protected by an overlay or local law, you, your builder and your contractors all need the right permit for any work near it. Banyule's guidance is that if a protected tree is damaged during construction, you could potentially be fined or otherwise prosecuted.
A neighbour's tree close to the boundary
A tree on the other side of the fence can still have a zone that reaches onto your block. Banyule, for example, requires an arborist's report where an application affects protected trees on adjoining properties. Tell whoever is quoting the demolition about any large trees next door.
Street trees
Trees on the nature strip are generally the council's. Where a zone is wider than the nature strip, Wyndham requires the fencing to follow the back of the kerb and the edge of the footpath. Truck and excavator access over a nature strip is where street trees usually come into play on a demolition.
Tree permits vs demolition approvals
Trees sit outside the approvals that most people think of for a demolition:
| Approval | Who decides | Does it cover trees? |
|---|---|---|
| Tree permit (overlay or local law) | Council | Yes. This is the one that applies to removing, lopping or working near a tree |
| Section 29A report and consent | Council | No. It's sign-off on demolishing the building. How Section 29A works |
| Building permit for demolition | Building surveyor | No. It covers the building work, not the tree controls |
Because a tree permit is a separate approval, it can add time if one is needed. For where it fits in the overall sequence, see how long house demolition takes.
What this means in Melbourne's South East
Tree rules are set council by council, so the answer for a block in Mount Eliza can be very different from one in Dandenong. On the Mornington Peninsula, the Vegetation Protection Overlay covers parts of several townships. In Frankston, the council's Tree Protection Local Law No. 22 means a permit may be needed to remove, prune or carry out works near a tree. Thresholds and rules change, so check the current version with the council. Other councils in the region have their own overlays and local laws.
If you're planning a house demolition and there are mature trees on the block, on the nature strip or next door, mention them when you ask for a quote. It's far easier to plan access and fencing before the job is booked than on the day.
General information only. This guide summarises council and planning guidance as at the date above. It isn't legal advice, and tree controls and thresholds change and differ between councils. Confirm what applies to your property with your council before any tree is removed, lopped or worked near.
Common questions
What is a tree protection zone?
A tree protection zone (TPZ) is the area around a tree that is fenced off during building and demolition work so its roots and trunk are not damaged. Under Australian Standard AS 4970-2009 its radius is 12 times the trunk diameter measured at 1.4 metres above ground, with a minimum radius of 2 metres. Machinery, parking, refuelling, stockpiles and digging are kept out of it.
How do I work out the tree protection zone for a tree?
Measure the trunk diameter at 1.4 metres above ground and multiply it by 12 to get the radius in the same units. A tree with a 40 cm trunk has a TPZ radius of 4.8 metres. The radius is never less than 2 metres, and the Standard caps it at 15 metres. An arborist will confirm the figure and set the zone for any tree that needs a formal assessment.
Do I need a permit to remove a tree before a house demolition?
Possibly. It depends on the tree and the planning controls on the property, not on the demolition. A permit may be required under an overlay such as a Vegetation Protection Overlay, Environmental Significance Overlay or Significant Landscape Overlay, under native vegetation rules, or under a council local law. Check with your council before any tree is removed or lopped.
Does Section 29A demolition consent cover trees?
No. Section 29A consent is council sign-off on the demolition of the building. Any permit to remove, lop or work near a tree is a separate approval under the planning scheme or a council local law, and it can affect your timeline if it is needed.
Can a demolition go ahead close to a protected tree?
Often yes, if the tree is protected properly. Fencing is installed around the tree protection zone before demolition starts, and nothing is parked, stored, stockpiled or dug inside it. Where the work has to enter the zone, a small encroachment can be acceptable under AS 4970, but an encroachment of 10% or more is treated as major and may not be allowed without an arborist's assessment and council agreement.
What happens if a protected tree is damaged during demolition?
The property owner, builder and contractors can be held responsible. Banyule City Council, for example, says that if a protected tree is damaged during construction you could potentially be fined or otherwise prosecuted. Penalties and processes differ between councils.
Sources
- Wyndham City Council: Tree protection fact sheet (2019)
- Banyule City Council: Protection for trees and vegetation
- Victorian Law Reform Commission: Planning law and regulation affecting trees on private land
- Victoria Planning Provisions: Clause 42.02 Vegetation Protection Overlay
- Mornington Peninsula Planning Scheme: Schedule 1 to the Vegetation Protection Overlay
- Frankston City Council: Local laws for trees