Party walls in South Australia: what the Act says

What the Act means by a party wall

Section 3(1) defines a party wall as a wall built to separate 2 or more buildings, or a wall forming part of a building and built on the dividing line between adjoining premises for their common use, and it includes a common wall for the purposes of the Building Code.

Two further definitions frame the rest of the Division. The building owner is the owner of land on or in relation to which building work is or is to be performed. The adjoining owner is the owner of land that abuts — either horizontally or vertically — the land of a building owner.

The definition has two limbs joined by “or”, and only the second refers to the dividing line and common use. Whether a particular wall meets it is a question about that wall; the Act supplies the definition, not the answer for a given address.

Building a new party wall

Section 147(1) applies where an owner proposes to build a party wall, or to convert an existing structure into one, on any part of the line of junction with adjoining land. The building owner must serve notice on the adjoining owner describing the proposed wall. If the adjoining owner consents, the wall must be built in the position the two owners agree.

Paragraph (d) is short: a party wall cannot be built by the building owner without the consent of the adjoining owner. Paragraph (c) says the cost of building it is borne by the two owners in due proportion, taking into account the use each is likely to make of the wall.

Paragraph (e) requires the owners to create easements of support in respect of the wall over their respective land, and to have them registered under the Real Property Act 1886 or lodged under the Registration of Deeds Act 1935. In the absence of contrary agreement, the building owner is liable for the expenses of registration. For a party wall lawfully built before 1 January 1974 that conformed with the law at the time, section 147(2) allows either owner to require the other to create and register such an easement.

Working on an existing party wall

Section 148(1) gives a building owner six rights, “subject to obtaining any appropriate approval under this Act (and otherwise complying with this Act)”, and “in addition to, and without prejudice to, any rights under any other Act or at common law”: to make good, underpin or repair a party wall that is defective or out of repair; to pull down and rebuild one so defective that this is necessary or expedient; to raise and underpin one; to pull down one of insufficient strength for a proposed building, provided a wall of sufficient strength is then rebuilt; to cut into one; and to perform any other work prescribed by the regulations.

Section 148(2) adds a right to install flashings between two buildings, including so that a flashing overlaps a boundary.

Whether a particular piece of work needs an approval under the Act is not answered by Division 3.

Notice, and what the neighbour can ask for

Under section 148(4), except with the adjoining owner’s written consent, a building owner cannot exercise any of those rights without first serving, personally or by post, a written notice stating the nature and particulars of the proposed work and when it is to commence, in accordance with any requirements prescribed by the regulations. Those prescribed requirements are not reproduced here.

The adjoining owner has a reply. Section 148(5) allows them, by written notice, to require the building owner to carry out other work on the party wall reasonably necessary for their convenience; the building owner must comply unless doing so would cause loss or damage, or undue inconvenience or delay. Section 148(6) makes the adjoining owner liable for the expenses of that work.

The building owner carries three duties throughout. Section 148(3) makes them liable to make good any damage to adjacent premises and their contents caused by exercising a right. Section 148(7) requires reasonable steps to protect adjoining land or premises. Section 148(8) prohibits exercising a right in a manner or at a time that causes unnecessary inconvenience, and requires the work to be performed with due diligence.

Entry and cost

Section 149(1) allows a building owner, or an authorised agent or employee, to enter and remain on the adjoining owner’s land at any reasonable time to perform work under the Division. Section 149(2) requires notice of intention to enter, stating the proposed time, served before entry — or, in an emergency, as early as possible. Section 149(3), in full: "The building owner, or an authorised agent or employee, accompanied by a member of the police force, may break into the premises of the adjoining owner."

Section 150(1) repeats the principle of section 147(1)(c) for all party wall work: the expense is borne in due proportion, having regard to the use each owner is to make of the wall. Under section 150(2), within 28 days after completing work for which a contribution is payable, the building owner must serve an account showing the cost and the proportion claimed. If it remains unpaid 28 days after service, section 150(3) allows the building owner to seek a determination of the amount in a court of competent jurisdiction and recover it as a debt.

• What can stop or reshape a rebuild on a block
• When council must be told during an SA build
• Knockdown rebuild services