Two different Hornsbys
Hornsby Shire covers an unusually wide range of ground. The ridge running north from Waitara through Hornsby, Normanhurst, Thornleigh and Mount Colah sits on Wianamatta shale — deep clay that grew Blue Gum High Forest, and still carries mature Sydney blue gum, blackbutt and turpentine in back gardens.
Either side of that ridge the ground falls into Hawkesbury sandstone: Berowra Valley and the Georges Creek system to the west, Lane Cove National Park and Ku-ring-gai Chase to the east and north. Those gullies are angophora, Sydney peppermint, scribbly gum and red bloodwood country, with a completely different set of access problems.
What needs approval
Hornsby Shire runs its tree controls through its development control plan, with a size threshold, an exempt species list and additional requirements where biodiversity or bushfire overlays apply.
The complication in this shire is remnant vegetation. Blue Gum High Forest and Sydney Turpentine-Ironbark Forest are both critically endangered ecological communities and both survive in fragments along the shale ridge here. A stand of tall blue gums on a Normanhurst or Thornleigh block may be regulated at state level regardless of what the council's base threshold says. Get the mapping checked.
Bushfire and 10/50
The bushland interface at Hornsby Heights, Mount Colah, Mount Kuring-gai, Berowra and Cowan is substantial, and much of it is bushfire prone land. Where a property falls inside a mapped 10/50 entitlement area, trees within ten metres of a home may be removed and underlying vegetation cleared within fifty metres without council approval.
The mapping is what counts, not the view from the back fence. Check the address on the RFS tool first.
The removals that come up
Three recurring jobs.
Very large shale-grown eucalypts over houses. Forty-metre blue gums and blackbutts on the ridge, usually over a 1950s or 1960s brick home. Almost always a sectional dismantle with everything rigged and lowered, because there is rarely room to fell and rarely a path for a crane.
Storm-damaged trees on gully blocks. Split unions and failed limbs after a southerly, on properties where the tree is well below the house.
Bushfire-driven clearing. Fuel reduction and removal of trees close to the dwelling on interface blocks, within whatever the 10/50 mapping allows.
Access
Ridge suburbs are generally manageable — post-war subdivision with driveways and side gates that take a machine. Gully blocks are the opposite: steep falls behind the house, stairs, retaining walls and a long uphill hand-carry to the street. Be honest about which one you have when asking for a price, because it is the single biggest variable.
Nearby
Wahroonga and Chatswood sit along the same ridge, Berowra and Epping have lopping pages, and the North Shore region page covers the wider area.
Ring (02) 9000 1943, or read the removal service page and the cost guide.
Frequently asked questions
Is Hornsby Shire strict about tree removal?
It varies within the shire. A suburban block at Normanhurst or Waitara is handled fairly conventionally. A bushland-interface property at Hornsby Heights, Mount Colah or Berowra sits under additional biodiversity and bushfire provisions, and remnant Blue Gum High Forest anywhere in the shire carries state protection on top of the council rules.
My block backs onto Berowra Valley. Can I clear for fire safety?
Only if the address is inside a mapped 10/50 vegetation clearing entitlement area. Plenty of Hornsby Shire bushland-edge properties are, and plenty of neighbouring ones are not. Check the address on the NSW Rural Fire Service tool rather than assuming, then work within the ten-metre and fifty-metre limits it sets.
Why is a removal down the back of a gully block so expensive?
Because there is no route for a vehicle. The tree is often twenty or thirty metres below the driveway with stairs or a bush track as the only access, so every section of timber is carried uphill by hand to a chipper in the street. That carrying is the bulk of the labour, and it is why a gully block prices very differently from a flat one nearby.