Key legal question
Whether the cantonal authorities could supplement the municipal rule with an exception for facilities requiring greater height due to their function.
Extracted holding
Yes. The supplement was necessary because the municipal rule, without it, would generally prevent ordinary approval of mobile-phone antennas and conflict with federal telecommunications law.
Extracted reasoning
A municipal planning rule may not, under the guise of a general height limit, effectively bar mobile antennas across the whole building zone. If communes wish to regulate such facilities, they must use specific planning or police instruments consistent with federal law; the adopted rule did not do so.