Trees and development
Trees are important urban assets and provide us with environmental, aesthetic, cultural and economic benefits. Therefore, it's essential that trees are considered when developing to ensure their safety and health.
On 11 October 2016, the City adopted Amendment No. 9 and Local Planning Policy 6.11 Trees and Development. This was in response to the decline in the City’s tree canopy cover and to ensure we achieve our vision for 2030 of cool, liveable suburbs. The amendment sets out new design requirements for trees on development sites and aims to ensure all new developments valued at over $100,000 in the City include at least one tree per 500m² of land.
The amendment was approved by the Minister for Planning and came into effect on 24 October 2017.
Scheme Amendment 9 - FAQ's
How does Scheme Amendment 9 affect new developments in the City?
For land with a significant tree, you must either keep it, or plant one new advanced tree for every 500m² (or part thereof) of land being developed.
For land without a significant tree, you must plant one advanced tree for every 500m² (or part thereof) of land being developed.
All trees (either newly planted advanced trees or significant trees being retained), must be surrounded by a 9m² deep planting zone per tree, to allow growth to maturity.
These requirements apply to all development applications with a value over $100,000.
With the introduction of Scheme Amendment 9, am I still required to have a street tree?
Yes. In accordance with Local Planning Policy 6.11, Council may still impose a condition of development approval to require the planting of an advanced tree (at the applicant’s cost), on an abutting road reserve. This is in addition to the requirement to retain or plant one tree per 500m² (or part thereof) on land being developed.
If my property is less than 500m², do I need to plant a tree?
Yes. The requirement is for one tree per 500m² or part thereof (see the table below):
|Site area||Number of advanced tree to be planted (or existing trees retained)|
|Up to 500m²||1|
|501m² - 1,000m²||2|
|1,001m² - 1,500m²||3|
|1,501m² - 2,000m²||4|
|Over 2,000m²||1 for every 500m² (or part thereof).|
If my application has been approved can I remove tree/s that were conditioned to be retained or planted?
No. Trees must be maintained to allow for the tree/s to grow to maturity. This will provide shade and visual enhancement, adding value to your property.
What happens if the tree becomes unhealthy or dies?
You should consult a suitably qualified arborist to determine what action is required to improve its health and save it. If the tree dies, it should be removed safely, and a new advanced tree planted in its place.
Please contact the City’s Parks and Sustainability business unit before removing or replacing any planted tree which is subject to a condition of development approval. The City conducts annual aerial monitoring of tree canopy cover within Stirling. If a tree is removed or not planted, the City will be aware and may take compliance action against the landowner for non-compliance of their development approval.
Significant trees - FAQ's
What is a significant tree?
A significant tree is a woody plant, that is at least four (4) metres tall and meets one of the following criteria:
- For a single-trunk species, a trunk circumference of at least 500mm at a height of one (1) metre above ground level
- For a multi-trunk species, a trunk circumference of at least 250mm on two or more stems, at a height of one (1) metre above ground level.
Generally, The City will not accept palm or cactus species as significant trees for retention (or new advanced trees for installation).
How do I protect retained significant trees during construction of my development?
Trees which you have chosen to retain on your land, and trees on the adjacent verge, must be protected from accidental or wilful damage during demolition and construction.
A tree protection zone (TPZ) must be established around each tree. As a minimum, this should be 2.4m by 2.4m around the tree trunk.
Storage, excavation, vehicle and machinery parking, waste dumping, and any other activities harmful to the tree are prohibited within the tree protection zone.
The TPZ should be fenced, typically with four panels of temporary construction fencing (each 2.4m wide by 1.8m high). Footings and bracing to the fencing should be located above ground.
In some cases, the developer may have to submit a management plan that outlines how the tree will be retained and protected.
I have a significant tree on my property that I would like to retain, although I am worried it may pose a risk to my development. What are my options?
Retaining a significant tree and integrating it into your development can provide an excellent outcome for both the future occupants and the neighbourhood. With some early planning, a new property can be designed and constructed around a significant tree in such a way that it will not pose any substantial risk to the development, or damage to the tree.
If you are concerned about the risk that a significant tree may pose, we recommend that you engage a professional arborist (not a tree lopper) to make a quantified tree risk assessment (QTRA).
Before engaging an arborist, make sure that they are suitably qualified and hold a degree or diploma in arboriculture and certification with the International Society of Arboriculture. Tree loppers are not arborists and will not provide you with the expertise you need for your development.
The arborist will assess the structure and health of the tree and calculate the risk of damage from falling limbs. They should provide a report which includes a risk assessment and actions you can take to minimise risk of damage to both the tree and property. This will help developers and homeowners to balance safety with the benefit of tree retention.
In most cases, the cost of a QTRA will be less than the cost of tree removal.
Advanced trees - FAQ's
What is an advanced tree?
An advanced tree is one with a root ball of 90 litres (or larger), which is at least two metres in height and two years of age.
The City will accept a tree with a 45-litre root ball in lieu of trees with a 90-litre root ball, when local native trees are selected.
A list of suggested tree species is available at the end of this document. This is not a definitive list and applicants may suggest other species when submitting plans for a development application. Tree sizes are indicative. The site conditions could result in differing tree sizes. Applicants are responsible for researching and selecting species that are suited to their specific requirements and site conditions.
When does the advanced tree need to be planted?
The advanced tree(s) must be planted prior to occupation of the development
Where can I purchase an advanced tree?
Advanced trees (trees in 90-litre pots) are available from retail and wholesale nurseries. It may be necessary to place a special order some months in advance, to secure the desired species in the required size.
Can the advanced trees be installed in large pots, instead of in-ground?
No. Pots do not provide a sufficient space for trees to establish properly.
I have purchased land on a previously subdivided lot, and am developing my portion of this lot. Do I need to plant an advanced tree?
When a lot is subdivided and developed by separate owners, each individual property owner will be required to plant advanced trees. For example, if a 700m² lot is subdivided into three smaller lots, one advanced tree is required on each of the three lots, at the time of dwelling construction.
Space requirements for trees and deep planting zones - FAQ's
Why do I need to provide a 9m² deep planting zone for each tree?
Trees need space to grow and a tree’s root system is roughly the same size as its canopy. For a tree to be healthy, the roots need access to good quality uncompacted soil, and sufficient water and oxygen.
The minimum area required for a medium sized tree to grow healthily is 9m².
What configuration is acceptable for the 9m² deep planting zone?
The City encourages the 9m² to be provided as a space 3m by 3m.
The recommended minimum width of the deep planting zone around the tree is 2m (in which case the deep planting zone must be 2m x 4.5m to provide 9m²).
We recommend that trees be placed centrally within the space provided and be a minimum of 2m from a building, wall, fence or property boundary (including the front boundary).
What ground treatments are acceptable within the 9m² around the tree?
Any ground treatment which provides the tree with access to good quality soil (minimum 1.2m deep), and allows oxygen and water to infiltrate into the tree’s root zone is acceptable. Soil should be a mix of sand, peat and fertilisers (suited to the tree species), and should be free of building rubble and any material detrimental to the tree’s health.
Acceptable ground treatments within the 9m² soil area include:
- Garden beds
- Organic or inorganic mulch
- Raised decking – if a 1.2m deep soil area of minimum 9m² is provided below the deck and footings do not encroach into the soil area. Where decking is proposed around a new or existing tree, the construction details of the decking must be submitted for approval prior to implementation.
Concrete, brick paving, asphalt and any other impermeable, compacted surfaces are not permitted within the 9m² deep planting zone. The zone must also be free of buildings and other fixed structures such as pergolas, swimming pools, footings, fixtures, underground services (except irrigation for the tree), soak-wells etc.
Can the deep planting zone be covered by a roof (even partially)?
No. The entire 9m² area must be open to the air.
Can the 9m² deep planting zone around each tree include the verge or adjoining paved areas or driveways?
If I choose to retain a significant tree, do I still need the 9m² deep planting zone around it?
Yes. This will help to ensure the health of the existing tree.
Tree location - FAQ's
Can the advanced tree be located anywhere on the development site?
Trees may be planted in private courtyards, common property or communal open space areas. Trees cannot be planted in parking areas on your property, or on the verge.
We recommend that trees are planted a minimum of 2m from a building, wall, fence or property boundary (including the front boundary).
We also recommend that new trees are planted a minimum distance of 5m from any other tree to prevent a conflict between the canopies.
How to pick the best location for a tree
Trees in the right location can provide shade to cool your home and help to reduce wind speed. Consider planting your tree where it will provide the most benefit.
- Deciduous trees planted to the north of your home can provide shade in summer but let winter sunlight through to warm your home
- Evergreen trees planted to the west of your home and garden can help reduce the speed of stormy winter winds
- Trees planted to the east of your garden will help to reduce hot summer winds which are drying and stressful for many garden plants.
Other considerations include solar access and impact on solar panels, location of underground services and the proximity to building and wall footings.
Compliance - FAQ's
How will the City ensure compliance with the new tree requirements?
The City will impose appropriate conditions on development approvals.
The City undertakes yearly aerial monitoring of canopy cover in order to track tree planting and growth. This mapping is sensitive enough to detect the advanced trees required under Scheme Amendment 9.
What is the process for implementing this policy?
When submitting a development application, you must provide a plan that illustrates the location of existing retained tree(s) or new advanced tree/s, and the 9m² soil area for each tree.
Where new advanced trees will be installed, the plan should also include the proposed tree species. Where an existing tree(s) will be retained, photos of the tree should be submitted with the development application.
Following the City’s approval of the location, soil area and species, the advanced tree(s) must be planted by your building/landscape contractor prior to occupation of the development.
On development completion, the owner will be responsible for maintaining the tree(s) to ensure they grow to maturity.