Questione giuridica chiave
Whether the imposed servitude securing emission limits in the quarter plan was validly created under cantonal planning law and federal law.
Decisione estratta
The servitude lacked a sufficient legal basis under § 139(1) PBG/ZH for an emissions-related restriction and could not replace the written private-law servitude contract required by Art. 732 ZGB; this violated the derogatory force of federal private law.
Motivazione estratta
Cantonal planning law authorized compulsory easements only for land readjustment purposes linked to building and access, not for emission control. Emission limits under USG must be implemented through public-law instruments; creating a ground servitude instead bypassed federal private-law form requirements.