Key legal question
Whether the cantonal court acted arbitrarily in holding that the preliminary phase had not been mutually completed, so no fee was due for later project phases.
Extracted holding
The finding was not arbitrary, even if another view was conceivable.
Extracted reasoning
The tariff already allowed a rough cost estimate in the preliminary phase; the court could view the January 23, 1997 estimate as belonging to that phase. It was also not untenable to hold that the respondents were unaware that a ready-to-file project had already been prepared, so the preliminary phase had not been mutually concluded.