Between the escarpment and the sea, the Illawarra has steep slopes, rainforest gullies, exposed coastline and fast-growing new suburbs, and every one of them affects how trees and development fit together. Synertree provides independent arborist reports, Arboricultural Impact Assessments (AIAs) and project arborist services from Helensburgh to Gerringong. Arborist reports and AIAs start from $880 + GST plus travel (AIAs for one tree), with fixed quotations within 24 hours.
Arborist reports from $880 + GST plus travel · AIAs from $880 + GST plus travel for one tree · Fixed quotations within 24 hours · All reports are completed by an AQF Level 5 or AQF Level 8 Arborist
What's included in an AIA from $880 + GST plus travel (one tree): a basic development proposal. We supply our captured tree data to your architect and landscape architect, and their plans show the tree retention and removal plan. ArborCAD Tree Protection Plans aren't included. ArborCAD Tree Protection Plans and larger or complex sites are quoted separately on your plans, with a fixed quotation within 24 hours.
Northern Illawarra: Helensburgh, Otford, Stanwell Park, Coalcliff, Scarborough, Wombarra, Coledale, Austinmer, Thirroul, Bulli, Woonona, Bellambi, Corrimal, Tarrawanna, Balgownie, Fairy Meadow.
Wollongong and surrounds: Wollongong, North Wollongong, Gwynneville, Keiraville, Mount Keira, Mount Ousley, Mount Pleasant, West Wollongong, Figtree, Mangerton, Mount Saint Thomas, Unanderra, Berkeley, Dapto, Horsley, Kanahooka.
South to Kiama: Albion Park, Calderwood, Shellharbour, Shell Cove, Flinders, Lake Illawarra, Kiama, Kiama Heights, Jamberoo, Gerringong and the surrounding suburbs.
We work across the following council areas:
Our AIAs and arborist reports are prepared to suit each council's DA tree requirements, and to AS 4970:2025.
The escarpment and steep slopes. Many homes in the northern suburbs and on the foothills are built on steep, escarpment-fed slopes where trees help hold the ground. Cut and fill, retaining walls and drainage changes can affect both root zones and slope stability. Our AIAs assess each tree to AS 4970:2025 and work alongside your geotechnical advice to recommend construction methods that keep the tree and the slope stable.
Rainforest gullies and remnant trees. Creek lines and gullies below the escarpment often hold remnant rainforest and moist forest species, including figs, cabbage tree palms and Illawarra flame trees, along with tall eucalypts on the ridges. These trees can have high retention value. Where a site may also need ecological input, we'll tell you at the start so your programme isn't delayed.
Coastal exposure. From Stanwell Park to Gerringong, beachfront and headland trees grow in salt-laden wind. Norfolk Island pines, Banksias and coastal figs are common. Wind-shaped canopies aren't automatically defects, and a QTRA or ISA TRAQ tree risk assessment separates real hazards from trees that have adapted to the coast.
Growth areas and new estates. New release areas to the west and south are turning paddocks into streets. Retained paddock trees and newly planted street trees are easily damaged during construction. Accurate tree locations with survey-grade GNSS (Trimble DA2) to 1 cm accuracy, together with ArborCAD Tree Protection Plans, keep subdivision layouts and tree protection aligned.
Older cottages and knock-down rebuilds. In the older coastal and inner suburbs, small cottages on long lots are being replaced by larger homes and dual occupancies, which brings construction closer to established trees and neighbours' trees. A Pre-AIA at concept stage can save a redesign.
Clay and colluvial soils. Soils below the escarpment vary from heavy clays to loose, rocky colluvium. Roots behave differently in each. Non-destructive AirSpade investigation and LiDAR 3D root mapping show where significant roots are before footings are designed.
Q: Do you work in the Wollongong, Shellharbour and Kiama council areas?
A: Yes. We prepare arborist reports, AIAs and project arborist work across all three council areas, with reports prepared to suit each council's DA tree requirements.
Q: My block is on a steep escarpment slope. Do I need an arborist and a geotechnical engineer?
A: Often both. Trees and slope stability are linked. We assess the trees to AS 4970:2025 and coordinate our recommendations with your geotechnical advice.
Q: Can you survey trees on a new subdivision?
A: Yes. We locate trees with survey-grade GNSS to 1 cm accuracy and prepare the AIA and Tree Protection Plan together.
Q: How much does an arborist report cost in the Illawarra?
A: Arborist reports start from $880 + GST plus travel for 1–5 trees. AIAs start from $880 + GST plus travel for one tree on a basic development proposal. ArborCAD Tree Protection Plans and larger or complex sites are quoted separately on your plans, with a fixed quotation within 24 hours.
Email your plans, survey or photos to info@synertree.com.au for a fixed quotation within 24 hours.