Key legal question
Whether the cantonal court's findings on the renovation costs and the amount of Flumroc insulation were arbitrary under Art. 9 BV.
Extracted holding
No arbitrariness was shown; the complaint did not disprove the evidentiary basis relied on by the cantonal court.
Extracted reasoning
The alleged monitoring and later acceptance did not exclude unnoticed deviations, and the court relied on instructions from the appellant or his site manager, not solely on witness A.