In their interpretation, the provisions of Part
2 of this chapter shall be held to minimum requirements. It is not the intent of Part
2 of this chapter to abrogate any permit previously issued pursuant to law relating to the use of buildings or land; nor shall it be interpreted to interfere with the provisions of existing codes, laws or ordinances regarding building construction, health, safety or sanitation or with any private restrictions placed upon a property by covenant or deed; provided, however, that where Part
2 of this chapter requires a greater width or size of lot or of yards or other open spaces or requires a lesser height, bulk or ground coverage for buildings or, in general, imposes restrictions greater than those required in another law or local ordinance or regulation, the provisions of Part
2 of this chapter shall govern.