Mo. Rev. Stat. § 64.680

Wherever the county zoning regulations made under authority of sections 64.510 to 64.690 require a greater width or size of yards, courts or other open spaces, or require a lower height of buildings or a less number of stories, or require greater percentage of lots to be left unoccupied, or require a lower density of population, or require a more restricted use of land, or impose other higher standards than are required in any other statute, local order or regulation, private deed restrictions or private covenants, the regulations made under authority of sections 64.510 to 64.690 shall govern.