A building which intrudes onto an adjoining neighbour's land will normally be covered by the Encroachments Act 1944 (SA). Any overhanging structures or any part of a building below ground which crosses the boundary can encroach - provided it is a substantial structure of a permanent character. An ordinary boundary fence is not likely to be considered a structure for the purposes of the Encroachments Act 1994 (SA). However, the Supreme Court has held, for example, that a concrete driveway is [Clarke v Wilkie  SASR 134], and that the combined structure of a brush fence sitting atop a concrete plinth and retaining wall is a structure for the purposes of the Encroachments Act 1994 (SA) [see Hogarth v Karp and Anor  SASC 159].
For information on fences that are located on the incorrect boundary, see Fences.
If there is a dispute between adjoining owners about whether a building is encroaching or not, they can arrange for a survey or apply to the Supreme Court for a survey to be ordered. Once surveyed a person must not deliberately tamper with survey pegs (unless permitted under the Act) as it is an offence under the Survey Act 1992 (SA) s 52.
Where a building does encroach, either owner may apply to the Supreme Court for compensation to be paid to the owner on whose land the building encroaches and/or for the land encroached on to be transferred or leased to the encroaching owner, and/or for the removal of the encroachment.
In making its decision, the court will consider:
[Encroachments Act 1944 (SA) s 4(3)]
The way compensation is calculated is set out in s 5 of the Act.
Other legal actions relating to trespass are available to deal with an encroaching building. However, if any legal action has been taken by one owner (usually the one whose land is encroached on) in connection with these matters, the other owner can obtain an order that the matter be settled under the Encroachments Act 1944(SA) alone.