This chapter is not intended to repeal, abrogate, annul or interfere with any existing ordinance or enactment, or with any rule, regulation or permit adopted or issued thereunder, except insofar as the same may be inconsistent or in conflict with any of the provisions of this chapter; provided, however, that where this chapter imposes greater restrictions upon larger open spaces than are required by the provisions of such ordinance, enactment, rule, regulation, or permit, then the provisions of this chapter shall prevail.