Regulated and significant trees in Adelaide before building

What is a regulated tree in South Australia?

Section 3(1) of the Act defines a regulated tree two ways: “a tree, or a tree within a class of trees, declared to be regulated by the regulations”, or “a tree declared to be a significant tree, or a tree within a stand of trees declared to be significant trees, under the Planning and Design Code”. Section 3(2) adds that “any plant that is commonly known as a palm will be taken to be a tree.”

Regulation 3F(1) of the Planning, Development and Infrastructure (General) Regulations 2017 supplies the first limb. It declares as regulated “trees within a designated regulated tree overlay that have a trunk with a circumference of 1 m or more or, in the case of trees that have multiple trunks, that have trunks with a total circumference of 1 m or more and an average circumference of 310 mm or more, measured at a point 1 m above natural ground level.” Regulation 3(1) defines that overlay as “an overlay identified under the Planning and Design Code as a designated regulated tree overlay”.

PlanSA’s FAQ on protecting regulated and significant trees calls it the Regulated and Significant Tree Overlay and points to the SA Property and Planning Atlas for its mapping. Whether a block sits inside it is a question about that address.

What is a significant tree, and where is the significant tree register?

The Act’s definition of significant tree also has two limbs. The first is a tree, or a stand of trees, declared significant under the Planning and Design Code. Section 68(1) lets the Code make that declaration where a tree “makes a significant contribution to the character or visual amenity of the local area”, is indigenous, rare or endangered or part of remnant native vegetation, is an important habitat for native fauna, or satisfies criteria prescribed by the regulations. Regulation 18A prescribes one: that the tree or stand “makes a significant contribution to the urban tree canopy of the local area.” Section 68(3) requires the Code to identify the location of such a tree or stand.

The second limb is measured. Under regulation 3F(2), a regulated tree under regulation 3F(1) is taken to be significant if it “has a trunk with a circumference of 2 m or more or, in the case of a tree with multiple trunks, has trunks with a total circumference of 2 m or more and an average circumference of 625 mm or more, measured at a point 1 m above natural ground level”.

The sources read for this note do not use the phrase significant tree register. PlanSA’s FAQ refers to “any tree identified as a significant tree in Part 10 of the Code”, and the State Planning Commission’s 2024 Proposal to Initiate records that Part 10 was created when the Code took effect in 2021, to define the trees previously declared significant by council development plans. Whether a listed tree stands on or near a block is checked for that address, in the Code or with the council.

How to check a tree before building or a knockdown rebuild

The regulations set the method. The trunk is measured “at a point 1 m above natural ground level”, and regulation 3F(3) states that for a multi-trunk tree the measurement uses “the actual circumference of each trunk and without taking into account any space between the trunks.”

Regulation 3F(4) then provides that subregulations (1) and (2) do not apply to five kinds of tree: (a) “a tree located within 3 m of an existing dwelling or an existing in-ground swimming pool, provided that the tree is on the same allotment as the dwelling or pool”, other than Agonis flexuosa (Willow Myrtle) or any tree of the genus Angophora, Corymbia or Eucalyptus; (b) “a tree of a species designated (from time to time) by the Minister by notice published on the SA planning portal”; (c) “a tree belonging to a class of plants to which a declaration by the Minister under Part 9 Division 1 of the Landscape South Australia Act 2019 applies”; (d) “a tree that may not be cleared without the consent of the Native Vegetation Council under the Native Vegetation Act 1991”; and (e) “a tree planted as part of a woodlot, orchard or other form of plantation created for the purpose of growing and then harvesting trees or any produce.”

Regulation 3F(5) sets how the 3 m is measured: “from the base of the trunk of the tree (or the nearest trunk of the tree to the dwelling or swimming pool) to the nearest part of the dwelling or swimming pool at natural ground level.” Schedule 4 clause 18(2) uses the same method for the distances in that clause.

Those exclusions are written against subregulations (1) and (2) only. The Note printed under regulation 3F(5) records that a tree may also be declared significant by the Planning and Design Code, and that “such a declaration has effect independently from those subregulations.” The 3 m exclusion is also written by reference to an existing dwelling; the note on what can stop a rebuild sets out why that matters once the house is to be demolished.

The definition of tree-damaging activity in section 3(1) is not limited to the land the tree stands on: it includes “any other act or activity that causes any of the foregoing to occur”. How it applies to a tree on neighbouring land is confirmed with the relevant authority for the address. A street tree on council land can itself be a regulated tree; council requirements for driveway crossovers apply as well, and are covered in the driveway crossover note.

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What counts as tree-damaging activity?

Paragraph (h) of the Act’s definition of development reads: “in relation to a regulated tree—any tree-damaging activity”. Section 101 provides that “no development may be undertaken unless the development is an approved development.”

Section 3(1) defines tree-damaging activity as “the killing or destruction of a tree”, “the removal of a tree”, “the severing of branches, limbs, stems or trunk of a tree”, “the ringbarking, topping or lopping of a tree” or “any other substantial damage to a tree”, and it “does not include maintenance pruning that is not likely to affect adversely the general health and appearance of a tree or that is excluded by regulation from the ambit of this definition”. PlanSA’s FAQ describes the controlled activities as including substantial damage to a regulated tree “including to its root system.”

Regulation 3F(6) excludes pruning that “does not remove more than 30% of the crown of the tree”, that is required to remove dead or diseased wood, branches that pose a material risk to a building, or branches posing a material risk to people in an area frequently used by them, and that is — “in the case of a tree on land owned by, or under the care, control and management of, a council—undertaken by or on behalf of the council at any time”, or “in any other case—undertaken at least 5 years after pruning of a kind referred to in this subregulation was last undertaken in relation to the tree”.

The definition does not list excavation or trenching by name; whether particular work near a tree falls within it is confirmed with the relevant authority for the address.

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Tree removal before building: the application and who assesses it

Section 82 of the Act lists the bodies that can be a relevant authority, including assessment panels, an assessment manager, an accredited professional and a council; sections 93 to 99 and the Regulations decide which one deals with a given application. PlanSA’s FAQ states that “the Assessment Manager of the relevant council is usually responsible” for applications about regulated and significant trees, and that they are lodged on the PlanSA portal or at the principal office of the relevant authority. Regulation 48 applies “if an owner of land to which an application for a tree-damaging activity in relation to a regulated tree relates is not a party to the application”: the relevant authority must give the owner notice of the application within the period set in regulation 48(a), and must give due consideration in its assessment to any submission made within the period specified in regulation 48(b).

On reports, section 119(7) says a relevant authority “should”, unless it considers special circumstances apply, seek to assess whether a tree is significant “without requesting the applicant to provide an expert or technical report”; section 119(8) applies the same principle to assessing an application about a regulated tree that is not significant. Where such a report is provided, regulation 37 sets the qualification as “a Diploma in Arboriculture recognised in the Australian tertiary training system, or a comparable or higher qualification.”

Some acts fall outside the definition of development. Schedule 4 clause 18(1) excludes tree-damaging activity in relation to a regulated tree where, among other cases, “the tree is dead”, or “the tree is within 20 m of a dwelling in a Medium or High Bushfire Risk area within a Hazards (Bushfire Protection) Overlay”. Regulation 3C(3) states that no Schedule 4 exclusion applies in respect of a State heritage place. Section 137(2) separately provides that the requirement to obtain approval for tree-damaging activity in relation to a regulated tree does not apply if the activity is being carried out “under Part 5 of the Electricity Act 1996”, “under, or in connection with the operation of, an order under section 254 or 299 of the Local Government Act 1999”, or “under another Act, or specified provisions of another Act, prescribed by the regulations for the purposes of this subsection.”

Section 136 covers urgency. Where tree-damaging activity in relation to a regulated tree must be undertaken as a matter of urgency “to protect any person or building” or “in any other circumstance of a prescribed kind”, a person may undertake it. The person must then notify the relevant authority in accordance with the regulations; the activity must, so far as is reasonably practicable, “be undertaken to cause the minimum amount of damage to the tree”; and, except in circumstances prescribed by the regulations, the owner of the land “must, as soon as practicable after the occurrence of the activity and in any event within the prescribed period, apply for the appropriate development authorisation”. Regulation 63(3) prescribes that period, “or such longer period as the relevant authority may allow”.

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Replacement trees or an offset payment

Section 127(4) provides that where a development authorisation provides for the killing, destruction or removal of a regulated or significant tree, the relevant authority “must apply the principle” that it be subject to a condition that “the prescribed number of trees (of a kind determined by the relevant authority) must be planted and maintained to replace the tree”, with “the cost of planting to be the responsibility of the applicant or any person who acquires the benefit of the consent and the cost of maintenance to be the responsibility of the owner of the land”.

Regulation 59(1) prescribes the number: “2 trees to replace the regulated tree”, or “3 trees to replace the significant tree”. Under regulation 59(2) a replacement tree cannot be of a species designated under regulation 3F(4)(b) for that location, and “cannot be planted within 3 m of an existing dwelling or an existing in-ground swimming pool.”

Section 127(6) allows the relevant authority, “on the application of the applicant”, to determine that a payment calculated under the regulations be made into the relevant fund instead of planting one or more replacement trees. Under section 127(7) that fund is the council’s urban trees fund for the area where one exists, and otherwise — or where the relevant authority is the Commission, or an assessment panel appointed by the Minister or a joint planning board — the Planning and Development Fund. Section 200(1) lets a council, with the approval of the Minister, establish an urban trees fund for an area it designates.

Section 127(8) disapplies subsections (4) and (6) where the tree is of a class excluded by the regulations, or where the relevant authority determines that an exemption is appropriate in a particular case “after taking into account any criteria prescribed by the regulations” and the Minister concurs.

What changed in 2024, and what is still only a proposal

The State Planning Commission’s Proposal to Initiate the Tree Protection and Planting Code Amendment, signed on 13 August 2024, records the amendments made to the Regulations in May 2024: the regulated tree measurement fell from 2 m to 1 m, the significant tree measurement from 3 m to 2 m, and the proximity exclusion from 10 m to 3 m of an existing dwelling or in-ground pool, with Angophora and Corymbia added to the genera it does not cover. Exempt species moved from a list in the Regulations to a ministerial notice on the SA planning portal, and regulation 18A was added.

The legislative history of the Regulations records a further amendment to regulation 3F(4) and (6) in force from 7 November 2025. The regulation text quoted on this page is Version 4.12.2025.

The Proposal to Initiate itself is not law. It states that it “forms the basis for the preparation of a proposed amendment to the Planning and Design Code”, and sets out a scope that includes reviewing the spatial application of the Regulated and Significant Tree Overlay and how tree-damaging activity near dwellings and in-ground pools is assessed. The Commission makes recommendations to the Minister, who decides whether to adopt, alter or refuse an amendment. Where it has reached since is not covered by the sources for this note; the Code as it applies to an address is what governs.