In the interpretation and application of the provisions of this subchapter, such provisions shall be held to be the minimum requirements adopted for the promotion of the health, safety, morals or the general welfare of the Virgin Islands. It is not intended by this subchapter to repeal, abrogate, annual or in any way impair or interfere with any provisions of laws or any rules or regulations previously adopted pursuant to law, relating to the use of buildings or land, nor is it intended to interfere with or abrogate or annul any easements, covenants or other agreements between parties; provided, however, that where this subchapter imposes a greater restriction upon the use, erection, alteration or extension of buildings, or use of land, or upon the number of square feet of lot area per family, or where the yard or building line requirements are more restrictive than the requirements imposed by such existing provisions of law, or by such rules or regulations or by such covenants or arrangements, the provisions of this subchapter shall control.