Adelaide block check
Regulated and Significant Trees in Adelaide: What Triggers a Report
Quick answer
A Regulated Tree in South Australia has a single-trunk circumference of 1.0 metres or more, measured 1.0 metres above natural ground level. A Significant Tree has a circumference of 2.0 metres or more. Both are protected by planning law and any works within their Tree Protection Zone need an arborist report.
South Australian planning law protects certain trees. In built-up Adelaide the trigger points are strict, and getting them wrong can stop a project. Before you decide where the house goes, you need to know which trees on and near your block are protected.
Public source: PlanSA: Significant and Regulated Trees (2024 reform)Field measurement
How to check whether a tree on your block is protected
- 1
Confirm the overlay applies
Check on SAPPA whether your parcel sits under the Regulated and Significant Tree Overlay. If not, statewide tree protection does not apply.
- 2
Identify the trees
Walk the block perimeter. Note every established tree, plus any protected tree on a neighbour whose canopy or root zone reaches your boundary.
- 3
Measure at 1.0 metre above ground
Use a soft tape. Measure the circumference of the trunk at exactly 1.0 metre above natural ground level. For multi-trunk trees, sum all trunks above the ground fork.
- 4
Compare against the thresholds
Single trunk 1.0 metres or more, or multi-trunk with combined 1.0 metres and average 310 mm, is Regulated. Single trunk 2.0 metres or more, or multi-trunk 2.0 metres combined and 625 mm average, is Significant. Some species and individually declared trees are always Significant, per Part 10 of the Code.
- 5
Commission an arborist report
Any development that removes, damages, or builds within the Tree Protection Zone of a Regulated or Significant Tree needs an arborist report from a suitably qualified consulting arborist. Commission the report before you finalise the design.
Watch: Homes By Homes podcast, episode 91
How Trees Can Impact Your Build and Cost You Thousands
A practical episode on how protected trees show up on your block and how the build has to work around them.
Section 1
What counts as a Regulated Tree
A tree with a single-trunk circumference of 1.0 metre or more measured at 1.0 metre above natural ground level. Multi-trunk trees qualify if their combined circumference reaches 1.0 metre and the average is at least 310 mm. Thresholds were tightened by the 2024 South Australian reform (previously 2.0 metres), so a lot of Adelaide trees that were unregulated a year ago are now protected.
Section 2
What counts as a Significant Tree
A tree with a single-trunk circumference of 2.0 metres or more measured at 1.0 metre above natural ground level. Multi-trunk trees qualify if the total is 2.0 metres and average is at least 625 mm. Significant Trees carry stronger protection than Regulated Trees. Some individually declared trees are always Significant regardless of size (listed in Part 10 of the Planning and Design Code).
Section 3
Neighbouring trees matter too
A protected tree in a neighbour's yard can still constrain your build if any part of its Tree Protection Zone (typically twice the canopy radius) extends onto your block. Root and canopy zones can force you to shift footprints, retain existing driveways, or redesign footings.
Section 4
When you need an arborist report
Any development application that proposes to remove, damage, or build within the Tree Protection Zone of a Regulated or Significant Tree needs an arborist report from a suitably qualified consulting arborist. The report assesses tree health, protection zone extent, and impact of the proposed works.
Section 5
Design implications
Protected trees rarely stop a project outright, but they routinely shrink the buildable footprint. Common outcomes: footings shifted away from the tree, pier-and-beam foundations to reduce root damage, driveway relocated, or the entire house rotated. Design around the tree first; do not squeeze it in later.
Section 6
What to check on your block today
Walk the perimeter. Any tree with a trunk you cannot comfortably wrap both arms around at chest height is worth measuring. Also check street trees on the verge, which are council-owned but still protected. If in doubt, get an arborist to visit before you commission a design.
What to do next
Keep reading
Find a town planner
Overlay-heavy block? A planner reads the code and pre-lodges advice.
Learn moreFind a private certifier
Ready for Planning + Building Rules Consent? A certifier can move fast.
Learn moreFind a building designer
Need drawings that respect the overlay? Start with a designer.
Learn moreCouncil approvals in Adelaide
The full pillar covering PlanSA, DCS levies, and the council pathway.
Learn moreThis is general planning and technical information drawn from public sources. It is not legal, planning, or engineering advice. Rules and overlays change; always confirm current requirements directly through SAPPA and engage a qualified professional (town planner, building designer, private certifier, arborist, or geotechnical engineer) for your specific block.