It is not intended by this chapter to repeal, abrogate, annul or in any way impair or interfere with existing provisions of other laws or ordinances, except those specifically or implicitly repealed by this chapter, or of any private restrictions placed upon property by covenant, deed or other private agreement unless repugnant hereto. Where this chapter imposes a greater restriction upon the use of buildings or premises or upon the height of 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.