Excavation on adjacent land: protection against settlement damage

The law of neighbours protects land not only against noise and dust but also against the withdrawal of its support. Section 364b ABGB provides that a plot may not be deepened in such a way that the soil or building of the neighbour is deprived of its necessary support. A deep excavation close to the property boundary can bring about exactly that.

The provision contains a decisive qualification, however: the withdrawal of support is permissible so far as the person doing the deepening provides for sufficient alternative reinforcement. Whoever digs an excavation must therefore answer, through suitable securing, that no damage arises to the neighbouring land. If that precaution is omitted, the deepening in this form is impermissible.

Section 364b ABGB gives rise to a claim to refrain from the endangering construction work. Where the builder is also at fault, for example because they omitted necessary securing, damages for the settlement damage that has occurred additionally come into consideration. Both claims may stand side by side.

An important rationale applies where the damaging construction work rests on an official authorisation. Where interference comes from an officially authorised installation, the neighbour generally cannot have it enjoined under section 364a ABGB. In place of the defence comes a fault-independent compensation claim in money.

The courts apply this rationale by analogy to damage from authorised construction work that could not be prevented despite the permit. Where the damage to your building therefore could not be averted because the construction work was covered by an authorisation, a balancing compensation in money under neighbour law is open to you. You do not need to prove any misconduct for this.

In practice it is often disputed whether the construction work was authorised in the sense that matters here and what amount of compensation is due. The distinction between an injunction and damages under section 364b ABGB on the one hand and monetary compensation under section 364a ABGB on the other is therefore often the first point that a legal assessment clarifies.

Settlement damage can only be enforced where its cause is established. You must prove that precisely the withdrawal of support through the deepening caused the damage to your building. This connection is as a rule clarified by an expert opinion that compares the condition before and after the works.

Early preservation of evidence is therefore decisive. Whoever records the condition of their building before the works begin and documents the changes during the excavation secures the basis of their claim. Once the excavation is backfilled and the condition changed, the cause can often only be proven with difficulty.

Besides photographs and a log, judicial preservation of evidence comes into consideration, which records the condition for later proceedings. How best to proceed here is explored in our article on preserving evidence before construction litigation.

The protection of support is to be distinguished from immissions. Section 364 para. 2 ABGB concerns interference such as noise, dust, odour or vibration that spreads from the building site onto your land. The question here is whether these exceed the locally customary level and substantially impair use.

Section 364b ABGB, by contrast, concerns the physical withdrawal of support. What matters is not interference acting through the air but that the soil or building is deprived of its load-bearing basis. This different basis decides which claim works.

In practice both areas can coincide. Vibrations during the excavation fall under immissions, the withdrawal of support thereby triggered under section 364b ABGB. An accurate classification of the facts is therefore the basis of every legal assessment.

Document the condition of your building comprehensively, ideally before the neighbouring site begins: dated photographs of the facade and the interior, a log of existing cracks and where possible measurements. Record every new change during the excavation. These records form the basis for every legal assessment.

First seek a conversation with the builder or the building owner and put your complaint in writing. Ask what securing is planned for the excavation. If that proves unsuccessful or settlement occurs, examine whether an injunction, damages or monetary compensation is the right path.

If the other side does not respond or the damage grows, early legal advice is sensible. A legal assessment quickly clarifies which of the routes under neighbour law works in your case and how to enforce your claims. An overview is provided on our focus page on construction damages and liability.