Key legal question
Whether the municipal and cantonal authorities arbitrarily applied the setback rule by placing the larger setback on the north side instead of the main/south-facing facade.
Extracted holding
Yes. The only rationale accepted by the cantonal court was arbitrary because a better use of the parcel is not a lawful basis for deviating from the rule; the setback should have been required on the southwest/main facade.
Extracted reasoning
Article 57 BG makes the larger setback the rule before the main or south-facing facade. On the facts, the southwest side was the main facade, and shifting the larger setback to the north merely improved buildability. That is incompatible with the neighbor-protective function of setback rules.