In its decisions 5D_105/2016 of April 12, 2017, and 6B_751/2017 of March 29, 2018, the Federal Supreme Court dealt with precisely this question.
The right to cut back branches and roots under Article 687 of the Swiss Civil Code is a special form of self-help and may be exercised if branches or roots from a neighboring property grow over the property line and cause significant damage. In addition, a prior warning with a deadline must be issued to the owner of the plant. These requirements for cutting or trimming branches and roots that cross the boundary must be strictly observed in order to avoid committing a property violation yourself.
Significant damage occurs when there is excessive impairment of the neighboring property, for example, obstruction or hindrance to its use, e.g., in terms of construction work, excessive moisture, shadowing, or restrictions on walking or driving on the neighboring property. Excessiveness is assessed based on the specific circumstances.
Before exercising the right of removal, the neighbor must be warned in writing and given a reasonable deadline to remedy the problem themselves. They must be given sufficient time to do so, taking into account the growing season of the plant in question.
Whether the conditions for the right to cut back are met must always be assessed on a case-by-case basis. This necessarily includes the existence of actual damage and the plant owner’s failure to remedy the impairment within a reasonable period of time. Only then may the affected neighbor exercise the right to cut back and trim the plants or branches back to the property line.
If the conditions for the right of capping are not met and the neighbor nevertheless takes action, he cannot invoke the right of capping as a justification, which may result in criminal and civil law consequences.
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