Victoria: the Building and Plumbing Commission's Protecting adjoining properties.
New South Wales: section 177 of the Conveyancing Act 1919, and the Registrar General's Law of Support paper.
Queensland: the Building Act 1975 (Qld) and the Queensland Government's page on avoiding building disputes.
The notice before the work
In Victoria, an owner proposing building work has obligations to protect adjoining property from potential damage.
Adjoining property means land at risk of significant damage, and it can include a street, highway, lane, footpath, alley or right of way.
Where the work is close to or adjacent to a boundary, protection work may be required, and the owner must serve a notice on the adjoining owner with the details of what is proposed.
The notice is not alone. A survey of the adjoining property is prepared by the owner with the adjoining owner, recording all existing cracks and defects.
That record is signed or acknowledged as the agreed statement of the property's condition before the protection work begins.
The answer, and the window for it
The adjoining owner has 14 days from service of the notice to respond. The response can agree, disagree, or ask for further information.
Silence within that window is taken as agreement to the proposed protection work.
Disagreement does not stall the process at that point. The building surveyor examines the proposal and determines whether the protection work is appropriate.
The surveyor then gives both owners notice in writing of the determination.
Either owner can appeal the determination within 14 days to the Building Appeals Board.
Insurance and the record
The owner having the building work done must make sure insurance is in force against potential damage the protection work could cause to the adjoining property.
The policy has to protect the adjoining property, its occupiers and the general public while the works run, and for the 12 months after the work is finished.
The page warns that an ordinary construction and public liability policy will usually not meet the minimum cover.
The cover is for an amount agreed between the two owners, and a copy of the policy goes to the adjoining owner before the work starts.
Money also follows the process, not just the insurance: the owner is required by law to pay the expenses the adjoining owner incurs in protecting their interests.
Queensland
In Queensland, the Building Act 1975 defines building work to take in excavating or filling that may adversely affect the stability of a building or other structure, whether on the land where it sits or on adjoining land.
The same Act's section 75 works from the neighbourhood side. Where soil conditions, ground levels, excavation or filling make it necessary to protect land, buildings or structures in the neighbourhood of building work, two things follow.
Retaining walls must be built, or other suitable methods used, to prevent soil movement, and drainage of the land, buildings or structures must be provided.
The Queensland Government's own pages stay on the neighbourly ground: check with the local government and talk to neighbours before starting building work close to the boundary.
One further Queensland rule shapes who carries the work: a retaining wall built as a dividing fence is the full responsibility of the owner who wants it.
Such a wall normally benefits one property much more than the other.
New South Wales
New South Wales changed its law in 2000, when section 177 was added to the Conveyancing Act 1919.
The section states a duty of care for the right of support for land, for the purposes of the common law of negligence.
In its terms, a person must not do anything on or in relation to the supporting land that takes away the support that land gives to other land, called the supported land.
Supporting land takes in the natural surface, the subsoil, any water beneath it, and any part that has been reclaimed.
The duty stops short of support given by a building or structure standing on the supporting land, unless that building or structure has taken the place of support which the land gave in its natural or reclaimed state.
The duty can be excluded or changed by an express agreement between the person who owes it and the person it is owed to.
Such an agreement binds the agents of the person who owes the duty, and it binds a later owner of the supported land only if it is embodied in a registered easement for removal of support.
The right to agree to the removal of support is itself a right that can be created by an easement.
The section also abolishes any common law right to bring an action in nuisance over the removal of that support, and removal includes any reduction of the support.
The paper gives the change a date: since 1 August 2000, a claim over removed support has sounded in negligence rather than nuisance, apart from proceedings begun earlier.
Victoria
Victoria's route already runs through the notice and the survey set out above.
The two documents do different jobs: the survey freezes the condition of the adjoining property, and the insurance covers damage to it while the protection work is done and afterwards.
Where a dispute arises over the insurance cover or the adequacy of the survey, the Building and Plumbing Commission's page says it can be referred to the Building Appeals Board for resolution.
And a permit sits behind all of it: none issues until that process has been completed to the surveyor's approval.
The three answers, side by side
| State | What its rule asks for |
|---|---|
| Queensland | The Building Act 1975: excavating or filling that may adversely affect the stability of a structure on adjoining land is building work, and where protection is necessary the Act requires retaining walls or other suitable methods, and drainage. |
| New South Wales | A duty of care stated by the Conveyancing Act 1919 since 2000: nothing may be done on or in relation to the supporting land that takes away the support it gives to the supported land, with the remedy in negligence since 1 August 2000. |
| Victoria | Protection work: a notice with the proposed details, 14 days for the adjoining owner to answer, and insurance covering the adjoining property for 12 months after the work. |
The three do not line up. One runs on a notice and insurance, one states a duty of care in its Act, and one puts a protection duty in its Building Act.
A dated timeline
How this area of law changed, and when
- 2000: section 177 is added to the New South Wales Conveyancing Act 1919.
- 1 August 2000: from this date, an action over removed support has sounded in negligence rather than nuisance, apart from earlier proceedings.
- Read on 13 October 2026 in the Internet Archive's capture of 26 February 2026: section 177 as set out above; Victoria's process runs on the notice, the 14 days and the 12 months of insurance; and Queensland's Building Act carries the section 75 requirement.