Consider "Area F" of Nanaimo has no building code or official community plan. They have an asphalt plant in a residential area and a sawmill next door to the elementary school.
This kind of thing is trivially taken care of by property prices. The sawmill will buy the land next to the asphalt plant, because no-one wants to live there. The land by the school will cost a little more, and people will choose to use it for living rather than for a sawmill that doesn't gain any advantage from being near a school.
There may be some problems to be solved by voluntarists, but land use planning is not one of them.
