It is not intended by this chapter to repeal, abrogate, annul or in any way impair or interfere with existing provisions of other laws and ordinances, except those specifically or impliedly repealed in this chapter, or any private restrictions placed on property by covenant, deed or other private agreement unless repugnant hereto. Where this chapter imposes a greater restriction upon the use of the buildings or premises or upon the height of the buildings, or lot coverage, or requires greater lot areas or larger yards, courts or other open spaces than are imposed or required by such existing provisions of law or ordinance or by such rules, regulations or permits or by such private restrictions, the provisions of this chapter shall control.