Key legal question
Whether the appellants could build the planned condominium extension and compel interior works in the respondents' unit
Extracted holding
The respondents could lawfully oppose the extension; the appellants had no right to carry out the works or to force interventions inside the respondents' unit without consent.
Extracted reasoning
The planned construction would cause substantial, lasting interference with the use and enjoyment of the respondents' unit. The cantonal court's finding that K.Y. had never accepted interior interventions was not arbitrary, and the abuse-of-rights argument failed because no contradictory conduct was established.