In interpreting and applying the provisions of this chapter, the regulations shall be held to be the minimum requirements for the promotion of the public safety, health, convenience, comfort, prosperity and general welfare. It is not intended by this chapter to interfere with or abrogate or annul any easements, covenants or other agreements between parties; provided, however, that where this chapter imposes a greater restriction upon the use of buildings or premises, this chapter shall control. Whenever any provision of this chapter applies to any use of land or buildings also regulated by any other town, county or state law, both or all of such regulations shall apply and such use shall, as a minimum, conform to the most restrictive provisions of such several laws.