Key legal question
Whether the roof terrace could be treated as a small annex under cantonal building law, allowing a 2 m boundary distance.
Extracted holding
Yes. The terrace was plausibly qualified as an uninhabited building part within the meaning of § 18 ABauV, so a reduced 2 m boundary distance was permissible.
Extracted reasoning
The structure was an open, uncovered rooftop sitting area with limited usability due to weather exposure and difficult access; the canton court's interpretation of § 18 ABauV was not arbitrary.