Before embarking on any building project which includes land excavation, it is important to understand the relevant provisions of neighbour law, which essentially means making use of your land so as not to prejudice your neighbour’s enjoyment of their own land.

A recent SCA judgment handed down in the case of Petropulos & Another v Dias (Case no 1055/2018) [2020], has provided some much-needed clarity on the duty of adjoining landowners to provide lateral support. Lateral support refers to the principle in property law that a person has the right to have his land supported by his neighbour's land and that adjoining landowners cannot alter the boundaries of their properties so as to weaken a neighbour’s property.

Confusion existed as to whether or not this duty extended only to situations of land in its natural state (unimproved land) as is the case in English law, or applied to both the land and all buildings and structures erected on it, as applied in Roman and Roman Dutch Law.

After considering the position the court concluded that English Law principles had no place in our law of lateral support and that the duty of lateral support is owed to both the land and buildings erected on it.

Liability for removal of lateral support is strict and requires no proof of fault or negligence. A neighbour who has suffered harm would need to show both a factual and legal causal link between the removal of lateral support and the harm suffered.

Factual causation will exist where the harmful conduct (removal of lateral support) was a substantial factor in the harm caused. This does not require certainty but evidence that it was the probable cause.

Legal causation is also necessary and in this regard factors such as reasonableness, fairness and justice, the absence or presence of any intervening circumstances, and legal policy will be considered. One cannot impute liability to a wrongdoer where the harmful conduct is too remotely connected to the harm caused.

In conclusion, the owner of a property has a natural right of lateral support from neighbouring properties, which right is not limited to land in its natural state but also extends to the buildings and other structures on the land. Where harm is established as a result of the removal of lateral support liability is strict and does not require proof of fault or negligence.