Q: Are municipal zoning ordinances halachically binding on account of dina d’malchusa? Does the municipality have a right to fine or punish those who violate them?
A: Municipal zoning ordinances are included in dina d’malchusa. This is because the townspeople, as a whole, can enact rules for public welfare, and fine or punish those who violate them. The elected officials and city council serve as the people’s representatives to enact and establish rules for the collective benefit and general welfare of the townspeople (C.M. 231:27-28).
According to most authorities, a majority vote suffices in this realm; there is no need for unanimous agreement (Pischei Teshuvah, C.M. 231:3,6).
Moreover, even according to those who maintain that dina d’malchusa does not apply in Eretz Yisrael, this is only regarding taxes and the like, which are for the benefit of the government. However, regarding municipal zoning laws, the townspeople can enact rules for their collective benefit (Pad”ar #12, p. 15).
Therefore, the municipality has the right to fine or demolish a structure built against the zoning ordinances.