What Needs Approval in the ACT: Earthworks, Retaining Walls, Sheds and Trees
Before the bucket goes in on a Canberra block: the ACT's exempt development rules, Dial Before You Dig, tree protection and the lease conditions that catch owners out.
This is general information for Canberra owners, not legal advice. Rules change; check the current position with Access Canberra or the ACT Planning Authority before you rely on it.
The ACT is different
Every residential block in Canberra is a Crown lease with conditions, the planning rules are territory-wide rather than council-by-council, and tree protection is stricter than in most states. The upside is that the rules are in one place; the downside is that people assume the rules from Queanbeyan apply and find out otherwise.
Retaining walls and earthworks
The ACT's exempt development provisions allow some retaining walls and minor earthworks without approval, subject to height limits, setbacks from boundaries and whether the wall supports other land or a driveway. Above the limits, or where a structural engineer is involved, you need approval and often a building licence for the builder. Check the current exempt development criteria on the ACT Planning website before you cut a terrace.
Sheds and slabs
Small sheds and slabs are exempt below size and height thresholds and outside setbacks; larger ones need approval. The earthworks for a shed pad on a slope can push a project over the exempt line.
Trees
The Tree Protection Act protects trees above a certain size on leased land, regulated trees, and anything on public land. Damaging the roots of a protected tree with an excavator is an offence. Check the tree register and get advice before digging within the drip line of a big eucalypt.
Underground services
Lodge a free Before You Dig Australia enquiry before every excavation. Canberra's suburbs have a lot of underground services, including the district heating and communications conduits in the older areas.
Easements and the lease
Many Canberra blocks carry easements for stormwater or services, and lease conditions can restrict what is built where. Both are on the lease and the plan; both will stop a wall or a shed.
On the border
Queanbeyan, Jerrabomberra and Googong are in New South Wales, where the NSW exempt and complying development codes apply instead. Bungendore and Yass are NSW council areas with their own rules.
Once the paperwork is done
The terracing guide on the Rippa ACT site covers the digging, and the Canberra jobs pages cover the machines for each.